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class="page-heading"> <h1 id="firstHeading" class="firstHeading mw-first-heading">Metallicity</h1> <div class="tagline"></div> </div> <ul id="p-associated-pages" class="minerva__tab-container"> <li class="minerva__tab selected"> <a class="minerva__tab-text" href="/wiki/Metallicity" rel="" data-event-name="tabs.subject">Article</a> </li> <li class="minerva__tab "> <a class="minerva__tab-text" href="/wiki/Talk:Metallicity" rel="discussion" data-event-name="tabs.talk">Talk</a> </li> </ul> <nav class="page-actions-menu"> <ul id="p-views" class="page-actions-menu__list"> <li id="language-selector" class="page-actions-menu__list-item"> <a role="button" href="#p-lang" data-mw="interface" data-event-name="menu.languages" title="Language" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet language-selector"> Language </a> </li> <li id="page-actions-watch" class="page-actions-menu__list-item"> <a role="button" id="ca-watch" href="/w/index.php?title=Special:UserLogin&returnto=Metallicity" data-event-name="menu.watch" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet menu__item--page-actions-watch"> Watch </a> </li> <li id="page-actions-edit" class="page-actions-menu__list-item"> <a role="button" id="ca-edit" href="/w/index.php?title=Metallicity&action=edit" data-event-name="menu.edit" data-mw="interface" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet edit-page menu__item--page-actions-edit"> Edit </a> </li> </ul> </nav>  <div id="mw-content-subtitle">(Redirected from <a href="/w/index.php?title=Metal-rich&redirect=no" class="mw-redirect" title="Metal-rich">Metal-rich</a>)</div> </div> <div id="bodyContent" class="content"> <div id="mw-content-text" class="mw-body-content"><script>function mfTempOpenSection(id){var block=document.getElementById("mf-section-"+id);block.className+=" open-block";block.previousSibling.className+=" open-block";}</script><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><section class="mf-section-0" id="mf-section-0"> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">For metallic and nonmetallic compounds, see <a href="/wiki/Metal" title="Metal">Metal</a> and <a href="/wiki/Nonmetallic_material" title="Nonmetallic material">Nonmetallic material</a>.</div> In <a href="/wiki/Astronomy" title="Astronomy">astronomy</a>, metallicity is the <a href="/wiki/Abundance_of_the_chemical_elements" title="Abundance of the chemical elements">abundance</a> of <a href="/wiki/Chemical_element" title="Chemical element">elements</a> present in an object that are heavier than <a href="/wiki/Hydrogen" title="Hydrogen">hydrogen</a> and <a href="/wiki/Helium" title="Helium">helium</a>. Most of the normal currently detectable (i.e. non-<a href="/wiki/Dark_matter" title="Dark matter">dark</a>) <a href="/wiki/Matter" title="Matter">matter</a> in the universe is either hydrogen or helium, and <a href="/wiki/Astronomer" title="Astronomer">astronomers</a> use the word "metals" as convenient shorthand for "all elements except hydrogen and helium". This word-use is distinct from the conventional chemical or physical definition of a <a href="/wiki/Metal" title="Metal">metal</a> as an electrically conducting solid. <a href="/wiki/Star" title="Star">Stars</a> and <a href="/wiki/Nebula" title="Nebula">nebulae</a> with relatively high abundances of heavier elements are called "metal-rich" when discussing metallicity, even though many of those elements are called <a href="/wiki/Nonmetal_(chemistry)" class="mw-redirect" title="Nonmetal (chemistry)">nonmetals</a> in chemistry. <figure class="mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:A_Swarm_of_Ancient_Stars_-_GPN-2000-000930.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6a/A_Swarm_of_Ancient_Stars_-_GPN-2000-000930.jpg/250px-A_Swarm_of_Ancient_Stars_-_GPN-2000-000930.jpg" decoding="async" width="250" height="262" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/6a/A_Swarm_of_Ancient_Stars_-_GPN-2000-000930.jpg/375px-A_Swarm_of_Ancient_Stars_-_GPN-2000-000930.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/6a/A_Swarm_of_Ancient_Stars_-_GPN-2000-000930.jpg/500px-A_Swarm_of_Ancient_Stars_-_GPN-2000-000930.jpg 2x" data-file-width="1777" data-file-height="1864"></a><figcaption>The <a href="/wiki/Globular_cluster" title="Globular cluster">globular cluster</a> <a href="/wiki/Messier_80" title="Messier 80">M80</a>. Stars in globular clusters are mainly older metal-poor members of <a href="/wiki/Population_II" class="mw-redirect" title="Population II">population II</a>.</figcaption></figure> <style data-mw-deduplicate="TemplateStyles:r886046785">.mw-parser-output .toclimit-2 .toclevel-1 ul,.mw-parser-output .toclimit-3 .toclevel-2 ul,.mw-parser-output .toclimit-4 .toclevel-3 ul,.mw-parser-output .toclimit-5 .toclevel-4 ul,.mw-parser-output .toclimit-6 .toclevel-5 ul,.mw-parser-output .toclimit-7 .toclevel-6 ul{display:none}</style><div class="toclimit-2"><div id="toc" class="toc" role="navigation" aria-labelledby="mw-toc-heading"><input type="checkbox" role="button" id="toctogglecheckbox" class="toctogglecheckbox" style="display:none"><div class="toctitle" lang="en" dir="ltr"><h2 id="mw-toc-heading">Contents</h2><label class="toctogglelabel" for="toctogglecheckbox"></label></div> <ul> <li class="toclevel-1 tocsection-1"><a href="#Metals_in_early_spectroscopy">1 Metals in early spectroscopy</a></li> <li class="toclevel-1 tocsection-2"><a href="#Origin_of_metallic_elements">2 Origin of metallic elements</a></li> <li class="toclevel-1 tocsection-3"><a href="#Stellar_populations">3 Stellar populations</a></li> <li class="toclevel-1 tocsection-4"><a href="#Common_methods_of_calculation">4 Common methods of calculation</a> <ul> <li class="toclevel-2 tocsection-5"><a href="#Mass_fraction">4.1 Mass fraction</a></li> <li class="toclevel-2 tocsection-6"><a href="#Chemical_abundance_ratios">4.2 Chemical abundance ratios</a></li> <li class="toclevel-2 tocsection-7"><a href="#Photometric_colors">4.3 Photometric colors</a></li> </ul> </li> <li class="toclevel-1 tocsection-8"><a href="#Metallicities_in_various_astrophysical_objects">5 Metallicities in various astrophysical objects</a> <ul> <li class="toclevel-2 tocsection-9"><a href="#Stars">5.1 Stars</a> <ul> <li class="toclevel-3 tocsection-10"><a href="#Relationship_between_stellar_metallicity_and_planets">5.1.1 Relationship between stellar metallicity and planets</a></li> <li class="toclevel-3 tocsection-11"><a href="#HII_regions">5.1.2 HII regions</a></li> </ul> </li> </ul> </li> <li class="toclevel-1 tocsection-12"><a href="#See_also">6 See also</a></li> <li class="toclevel-1 tocsection-13"><a href="#References">7 References</a></li> <li class="toclevel-1 tocsection-14"><a href="#Further_reading">8 Further reading</a></li> </ul> </div> </div> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(1)"><h2 id="Metals_in_early_spectroscopy">Metals in early spectroscopy</h2> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=1" title="Edit section: Metals in early spectroscopy" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div><section class="mf-section-1 collapsible-block" id="mf-section-1"> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Fraunhofer_lines.svg" class="mw-file-description"><noscript><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/2f/Fraunhofer_lines.svg/350px-Fraunhofer_lines.svg.png" decoding="async" width="350" height="103" class="mw-file-element" data-file-width="768" data-file-height="225"></noscript><span class="lazy-image-placeholder" style="width: 350px;height: 103px;" data-src="//upload.wikimedia.org/wikipedia/commons/thumb/2/2f/Fraunhofer_lines.svg/350px-Fraunhofer_lines.svg.png" data-width="350" data-height="103" data-srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/2f/Fraunhofer_lines.svg/525px-Fraunhofer_lines.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/2f/Fraunhofer_lines.svg/700px-Fraunhofer_lines.svg.png 2x" data-class="mw-file-element"> </a><figcaption>Solar spectrum with Fraunhofer lines as it appears visually.</figcaption></figure> In 1802, <a href="/wiki/William_Hyde_Wollaston" title="William Hyde Wollaston">William Hyde Wollaston</a><a href="#cite_note-eb-1">[1]</a> noted the appearance of a number of dark features in the solar spectrum.<a href="#cite_note-2">[2]</a> In 1814, <a href="/wiki/Joseph_von_Fraunhofer" title="Joseph von Fraunhofer">Joseph von Fraunhofer</a> independently rediscovered the lines and began to systematically study and measure their <a href="/wiki/Wavelength" title="Wavelength">wavelengths</a>, and they are now called <a href="/wiki/Fraunhofer_lines" title="Fraunhofer lines">Fraunhofer lines</a>. He mapped over 570 lines, designating the most prominent with the letters A through K and weaker lines with other letters.<a href="#cite_note-3">[3]</a><a href="#cite_note-4">[4]</a><a href="#cite_note-5">[5]</a> About 45 years later, <a href="/wiki/Gustav_Kirchhoff" title="Gustav Kirchhoff">Gustav Kirchhoff</a> and <a href="/wiki/Robert_Bunsen" title="Robert Bunsen">Robert Bunsen</a><a href="#cite_note-6">[6]</a> noticed that several Fraunhofer lines coincide with characteristic <a href="/wiki/Emission_spectrum" title="Emission spectrum">emission lines</a> identifies in the spectra of heated chemical elements.<a href="#cite_note-7">[7]</a> They inferred that dark lines in the solar spectrum are caused by <a href="/wiki/Absorption_(electromagnetic_radiation)" title="Absorption (electromagnetic radiation)">absorption</a> by <a href="/wiki/Chemical_element" title="Chemical element">chemical elements</a> in the solar atmosphere.<a href="#cite_note-8">[8]</a> Their observations<a href="#cite_note-9">[9]</a> were in the visible range where the strongest lines come from metals such as sodium, potassium, and iron.<a href="#cite_note-10">[10]</a> In the early work on the chemical composition of the sun the only elements that were detected in spectra were hydrogen and various metals,<a href="#cite_note-Meadows-11">[11]</a>: 23–24 with the term metallic frequently used when describing them.<a href="#cite_note-Meadows-11">[11]</a>: Part 2 In contemporary usage in astronomy all the extra elements beyond just hydrogen and helium are termed metallic. </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(2)"><h2 id="Origin_of_metallic_elements">Origin of metallic elements</h2> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=2" title="Edit section: Origin of metallic elements" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div><section class="mf-section-2 collapsible-block" id="mf-section-2"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Stellar_nucleosynthesis" title="Stellar nucleosynthesis">Stellar nucleosynthesis</a> and <a href="/wiki/Big_Bang_nucleosynthesis" title="Big Bang nucleosynthesis">Big Bang nucleosynthesis</a></div> The presence of heavier elements results from stellar nucleosynthesis, where the majority of elements heavier than hydrogen and helium in the Universe (metals, hereafter) are formed in the cores of stars as they <a href="/wiki/Stellar_evolution" title="Stellar evolution">evolve</a>. Over time, <a href="/wiki/Stellar_wind" title="Stellar wind">stellar winds</a> and <a href="/wiki/Supernova" title="Supernova">supernovae</a> deposit the metals into the surrounding environment, enriching the <a href="/wiki/Interstellar_medium" title="Interstellar medium">interstellar medium</a> and providing recycling materials for the <a href="/wiki/Protostar" title="Protostar">birth of new stars</a>. It follows that older generations of stars, which formed in the metal-poor <a href="/wiki/Chronology_of_the_universe" title="Chronology of the universe">early Universe</a>, generally have lower metallicities than those of younger generations, which formed in a more metal-rich Universe. </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(3)"><h2 id="Stellar_populations">Stellar populations</h2> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=3" title="Edit section: Stellar populations" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div><section class="mf-section-3 collapsible-block" id="mf-section-3"> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Treasures3.jpg" class="mw-file-description"><noscript><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Treasures3.jpg/220px-Treasures3.jpg" decoding="async" width="220" height="300" class="mw-file-element" data-file-width="940" data-file-height="1280"></noscript><span class="lazy-image-placeholder" style="width: 220px;height: 300px;" data-src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Treasures3.jpg/220px-Treasures3.jpg" data-width="220" data-height="300" data-srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Treasures3.jpg/330px-Treasures3.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Treasures3.jpg/440px-Treasures3.jpg 2x" data-class="mw-file-element"> </a><figcaption><a href="/wiki/Population_I" class="mw-redirect" title="Population I">Population I</a> star <a href="/wiki/Rigel" title="Rigel">Rigel</a> with <a href="/wiki/Reflection_nebula" title="Reflection nebula">reflection nebula</a> <a href="/wiki/IC_2118" title="IC 2118">IC 2118</a></figcaption></figure> Observed changes in the chemical abundances of different types of stars, based on the spectral peculiarities that were later attributed to metallicity, led astronomer <a href="/wiki/Walter_Baade" title="Walter Baade">Walter Baade</a> in 1944 to propose the existence of two different <a href="/wiki/Stellar_population" title="Stellar population">populations of stars</a>.<a href="#cite_note-12">[12]</a> These became commonly known as <a href="/wiki/Population_I" class="mw-redirect" title="Population I">population I</a> (metal-rich) and <a href="/wiki/Population_II" class="mw-redirect" title="Population II">population II</a> (metal-poor) stars. A third, earliest <a href="/wiki/Stellar_population" title="Stellar population">stellar population</a> was hypothesized in 1978, known as <a href="/wiki/Population_III" class="mw-redirect" title="Population III">population III</a> stars.<a href="#cite_note-13">[13]</a><a href="#cite_note-14">[14]</a><a href="#cite_note-15">[15]</a> These "extremely metal-poor" (XMP) stars are theorized to have been the "first-born" stars created in the Universe. </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(4)"><h2 id="Common_methods_of_calculation">Common methods of calculation</h2> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=4" title="Edit section: Common methods of calculation" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div><section class="mf-section-4 collapsible-block" id="mf-section-4"> Astronomers use several different methods to describe and approximate metal abundances, depending on the available tools and the object of interest. Some methods include determining the fraction of mass that is attributed to <a href="/wiki/Gas" title="Gas">gas</a> versus metals, or measuring the ratios of the number of atoms of two different elements as compared to the ratios found in the <a href="/wiki/Sun" title="Sun">Sun</a>. <div class="mw-heading mw-heading3"><h3 id="Mass_fraction">Mass fraction</h3> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=5" title="Edit section: Mass fraction" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div> Stellar composition is often simply defined by the parameters X, Y, and Z. Here X represents the mass fraction of <a href="/wiki/Hydrogen" title="Hydrogen">hydrogen</a>, Y is the mass fraction of <a href="/wiki/Helium" title="Helium">helium</a>, and Z is the mass fraction of all the remaining chemical elements. Thus <math display="block" xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle X+Y+Z=1}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>X</mi> <mo>+</mo> <mi>Y</mi> <mo>+</mo> <mi>Z</mi> <mo>=</mo> <mn>1</mn> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle X+Y+Z=1}</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b11c6e06a8964ed3dfce909f6418bd4caf850559" class="mwe-math-fallback-image-display mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.505ex; width:15.375ex; height:2.343ex;" alt="{\displaystyle X+Y+Z=1}"></noscript><span class="lazy-image-placeholder" style="width: 15.375ex;height: 2.343ex;vertical-align: -0.505ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b11c6e06a8964ed3dfce909f6418bd4caf850559" data-alt="{\displaystyle X+Y+Z=1}" data-class="mwe-math-fallback-image-display mw-invert skin-invert">  In most <a href="/wiki/Stars" class="mw-redirect" title="Stars">stars</a>, <a href="/wiki/Nebula" title="Nebula">nebulae</a>, <a href="/wiki/H_II_region" title="H II region">HII regions</a>, and other astronomical sources, hydrogen and helium are the two dominant elements. The hydrogen mass fraction is generally expressed as <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ X\equiv {\tfrac {m_{\mathsf {H}}}{M}}\ ,}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <mi>X</mi> <mo>≡</mo> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mrow> </msub> <mi>M</mi> </mfrac> </mstyle> </mrow> <mtext> </mtext> <mo>,</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ X\equiv {\tfrac {m_{\mathsf {H}}}{M}}\ ,}</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/c74f667b02ba256dc9c4d1104f646246e1c07da1" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.171ex; width:10.274ex; height:3.509ex;" alt="{\displaystyle \ X\equiv {\tfrac {m_{\mathsf {H}}}{M}}\ ,}"></noscript><span class="lazy-image-placeholder" style="width: 10.274ex;height: 3.509ex;vertical-align: -1.171ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/c74f667b02ba256dc9c4d1104f646246e1c07da1" data-alt="{\displaystyle \ X\equiv {\tfrac {m_{\mathsf {H}}}{M}}\ ,}" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  where M is the total mass of the system, and <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ m_{\mathsf {H}}\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mrow> </msub> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ m_{\mathsf {H}}\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/caac3a02d160d56b04ab1688da36c09505109399" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:4.598ex; height:2.009ex;" alt="{\displaystyle \ m_{\mathsf {H}}\ }"></noscript><span class="lazy-image-placeholder" style="width: 4.598ex;height: 2.009ex;vertical-align: -0.671ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/caac3a02d160d56b04ab1688da36c09505109399" data-alt="{\displaystyle \ m_{\mathsf {H}}\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  is the mass of the hydrogen it contains. Similarly, the helium mass fraction is denoted as <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ Y\equiv {\tfrac {m_{\mathsf {He}}}{M}}~.}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <mi>Y</mi> <mo>≡</mo> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> <mi mathvariant="sans-serif">e</mi> </mrow> </mrow> </msub> <mi>M</mi> </mfrac> </mstyle> </mrow> <mtext> </mtext> <mo>.</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ Y\equiv {\tfrac {m_{\mathsf {He}}}{M}}~.}</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2ef48beaad71fdbea048734f7e631d61eb8b0d0e" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.171ex; width:10.66ex; height:3.509ex;" alt="{\displaystyle \ Y\equiv {\tfrac {m_{\mathsf {He}}}{M}}~.}"></noscript><span class="lazy-image-placeholder" style="width: 10.66ex;height: 3.509ex;vertical-align: -1.171ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2ef48beaad71fdbea048734f7e631d61eb8b0d0e" data-alt="{\displaystyle \ Y\equiv {\tfrac {m_{\mathsf {He}}}{M}}~.}" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  The remainder of the elements are collectively referred to as "metals", and the mass fraction of metals is calculated as <math display="block" xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle Z=\sum _{e>{\mathsf {He}}}{\tfrac {m_{e}}{M}}=1-X-Y~.}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>Z</mi> <mo>=</mo> <munder> <mo>∑</mo> <mrow class="MJX-TeXAtom-ORD"> <mi>e</mi> <mo>></mo> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> <mi mathvariant="sans-serif">e</mi> </mrow> </mrow> </mrow> </munder> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>e</mi> </mrow> </msub> <mi>M</mi> </mfrac> </mstyle> </mrow> <mo>=</mo> <mn>1</mn> <mo>−</mo> <mi>X</mi> <mo>−</mo> <mi>Y</mi> <mtext> </mtext> <mo>.</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle Z=\sum _{e>{\mathsf {He}}}{\tfrac {m_{e}}{M}}=1-X-Y~.}</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/4252e32d18d533a40ee2857ecf6389901452304e" class="mwe-math-fallback-image-display mw-invert skin-invert" aria-hidden="true" style="vertical-align: -3.171ex; width:27.092ex; height:5.676ex;" alt="{\displaystyle Z=\sum _{e>{\mathsf {He}}}{\tfrac {m_{e}}{M}}=1-X-Y~.}"></noscript><span class="lazy-image-placeholder" style="width: 27.092ex;height: 5.676ex;vertical-align: -3.171ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/4252e32d18d533a40ee2857ecf6389901452304e" data-alt="{\displaystyle Z=\sum _{e>{\mathsf {He}}}{\tfrac {m_{e}}{M}}=1-X-Y~.}" data-class="mwe-math-fallback-image-display mw-invert skin-invert">  For the surface of the Sun (<a href="/wiki/Astronomical_symbols" title="Astronomical symbols">symbol</a> <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \odot }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>⊙</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \odot }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/e89e009eb8a8839c82aa5c76c15e9f2d67006276" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.505ex; width:1.808ex; height:2.176ex;" alt="{\displaystyle \odot }"></noscript><span class="lazy-image-placeholder" style="width: 1.808ex;height: 2.176ex;vertical-align: -0.505ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/e89e009eb8a8839c82aa5c76c15e9f2d67006276" data-alt="{\displaystyle \odot }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert"> ), these parameters are measured to have the following values:<a href="#cite_note-asplund-16">[16]</a> <table class="wikitable"> <tbody><tr> <th>Description</th> <th>Solar value </th></tr> <tr> <td>Hydrogen mass fraction</td> <td><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ X_{\odot }=0.7381\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <msub> <mi>X</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>⊙</mo> </mrow> </msub> <mo>=</mo> <mn>0.7381</mn> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ X_{\odot }=0.7381\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/0e962f2d70cb33abc99f73bfe09323a7acbda509" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:14.154ex; height:2.509ex;" alt="{\displaystyle \ X_{\odot }=0.7381\ }"></noscript><span class="lazy-image-placeholder" style="width: 14.154ex;height: 2.509ex;vertical-align: -0.671ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/0e962f2d70cb33abc99f73bfe09323a7acbda509" data-alt="{\displaystyle \ X_{\odot }=0.7381\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  </td></tr> <tr> <td>Helium mass fraction</td> <td><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ Y_{\odot }=0.2485\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <msub> <mi>Y</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>⊙</mo> </mrow> </msub> <mo>=</mo> <mn>0.2485</mn> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ Y_{\odot }=0.2485\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/7c29aecfeb635d5835011eb7e0f57d130a60ae63" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:13.58ex; height:2.509ex;" alt="{\displaystyle \ Y_{\odot }=0.2485\ }"></noscript><span class="lazy-image-placeholder" style="width: 13.58ex;height: 2.509ex;vertical-align: -0.671ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/7c29aecfeb635d5835011eb7e0f57d130a60ae63" data-alt="{\displaystyle \ Y_{\odot }=0.2485\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  </td></tr> <tr> <td>Metal mass fraction</td> <td><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ Z_{\odot }=0.0134\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <msub> <mi>Z</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>⊙</mo> </mrow> </msub> <mo>=</mo> <mn>0.0134</mn> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ Z_{\odot }=0.0134\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/09c8424275105eec538817554d5916c48ec41c49" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:13.817ex; height:2.509ex;" alt="{\displaystyle \ Z_{\odot }=0.0134\ }"></noscript><span class="lazy-image-placeholder" style="width: 13.817ex;height: 2.509ex;vertical-align: -0.671ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/09c8424275105eec538817554d5916c48ec41c49" data-alt="{\displaystyle \ Z_{\odot }=0.0134\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  </td></tr></tbody></table> Due to the effects of <a href="/wiki/Stellar_evolution" title="Stellar evolution">stellar evolution</a>, neither the initial composition nor the present day bulk composition of the Sun is the same as its present-day surface composition. <div class="mw-heading mw-heading3"><h3 id="Chemical_abundance_ratios">Chemical abundance ratios</h3> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=6" title="Edit section: Chemical abundance ratios" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div> The overall stellar metallicity is conventionally defined using the total hydrogen content, since its abundance is considered to be relatively constant in the Universe, or the <a href="/wiki/Iron" title="Iron">iron</a> content of the star, which has an abundance that is generally linearly increasing in time in the Universe.<a href="#cite_note-17">[17]</a> Hence, iron can be used as a chronological indicator of nucleosynthesis. <a href="/wiki/Iron" title="Iron">Iron</a> is relatively easy to measure with spectral observations in the star's spectrum given the large number of iron lines in the star's spectra (even though oxygen is the <a href="/wiki/Abundance_of_the_chemical_elements#Universe" title="Abundance of the chemical elements">most abundant heavy element</a> – see <a href="#H-II-region-anchor">metallicities in HII regions</a> below). The abundance ratio is the <a href="/wiki/Common_logarithm" title="Common logarithm">common logarithm</a> of the ratio of a star's iron abundance compared to that of the Sun and is calculated thus:<a href="#cite_note-Matteucci2001-18">[18]</a> <math display="block" xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \left[{\frac {\mathsf {Fe}}{\mathsf {H}}}\right]~=~\log _{10}{\left({\frac {N_{\mathsf {Fe}}}{N_{\mathsf {H}}}}\right)_{\star }}-~\log _{10}{\left({\frac {N_{\mathsf {Fe}}}{N_{\mathsf {H}}}}\right)_{\odot }}\ ,}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mrow> <mo>[</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mfrac> </mrow> <mo>]</mo> </mrow> <mtext> </mtext> <mo>=</mo> <mtext> </mtext> <msub> <mi>log</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>10</mn> </mrow> </msub> <mo>⁡</mo> <mrow class="MJX-TeXAtom-ORD"> <msub> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msub> <mi>N</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> </mrow> </msub> <msub> <mi>N</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mrow> </msub> </mfrac> </mrow> <mo>)</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mo>⋆</mo> </mrow> </msub> </mrow> <mo>−</mo> <mtext> </mtext> <msub> <mi>log</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>10</mn> </mrow> </msub> <mo>⁡</mo> <mrow class="MJX-TeXAtom-ORD"> <msub> <mrow> <mo>(</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msub> <mi>N</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> </mrow> </msub> <msub> <mi>N</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mrow> </msub> </mfrac> </mrow> <mo>)</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mo>⊙</mo> </mrow> </msub> </mrow> <mtext> </mtext> <mo>,</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \left[{\frac {\mathsf {Fe}}{\mathsf {H}}}\right]~=~\log _{10}{\left({\frac {N_{\mathsf {Fe}}}{N_{\mathsf {H}}}}\right)_{\star }}-~\log _{10}{\left({\frac {N_{\mathsf {Fe}}}{N_{\mathsf {H}}}}\right)_{\odot }}\ ,}</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/00a53cde09129128faa7e4d630374bd45b9817c4" class="mwe-math-fallback-image-display mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.671ex; width:44.793ex; height:6.343ex;" alt="{\displaystyle \left[{\frac {\mathsf {Fe}}{\mathsf {H}}}\right]~=~\log _{10}{\left({\frac {N_{\mathsf {Fe}}}{N_{\mathsf {H}}}}\right)_{\star }}-~\log _{10}{\left({\frac {N_{\mathsf {Fe}}}{N_{\mathsf {H}}}}\right)_{\odot }}\ ,}"></noscript><span class="lazy-image-placeholder" style="width: 44.793ex;height: 6.343ex;vertical-align: -2.671ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/00a53cde09129128faa7e4d630374bd45b9817c4" data-alt="{\displaystyle \left[{\frac {\mathsf {Fe}}{\mathsf {H}}}\right]~=~\log _{10}{\left({\frac {N_{\mathsf {Fe}}}{N_{\mathsf {H}}}}\right)_{\star }}-~\log _{10}{\left({\frac {N_{\mathsf {Fe}}}{N_{\mathsf {H}}}}\right)_{\odot }}\ ,}" data-class="mwe-math-fallback-image-display mw-invert skin-invert">  where <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ N_{\mathsf {Fe}}\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <msub> <mi>N</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> </mrow> </msub> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ N_{\mathsf {Fe}}\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/f16d4b78414b60893881f245a03ab05407260a22" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:4.925ex; height:2.509ex;" alt="{\displaystyle \ N_{\mathsf {Fe}}\ }"></noscript><span class="lazy-image-placeholder" style="width: 4.925ex;height: 2.509ex;vertical-align: -0.671ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/f16d4b78414b60893881f245a03ab05407260a22" data-alt="{\displaystyle \ N_{\mathsf {Fe}}\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  and <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ N_{\mathsf {H}}\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <msub> <mi>N</mi> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mrow> </msub> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ N_{\mathsf {H}}\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/872b0d4c7fa6873ae0665defa223ec78ac57f350" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:4.423ex; height:2.509ex;" alt="{\displaystyle \ N_{\mathsf {H}}\ }"></noscript><span class="lazy-image-placeholder" style="width: 4.423ex;height: 2.509ex;vertical-align: -0.671ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/872b0d4c7fa6873ae0665defa223ec78ac57f350" data-alt="{\displaystyle \ N_{\mathsf {H}}\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  are the number of iron and hydrogen atoms per unit of volume respectively, <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \odot }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>⊙</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \odot }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/e89e009eb8a8839c82aa5c76c15e9f2d67006276" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.505ex; width:1.808ex; height:2.176ex;" alt="{\displaystyle \odot }"></noscript><span class="lazy-image-placeholder" style="width: 1.808ex;height: 2.176ex;vertical-align: -0.505ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/e89e009eb8a8839c82aa5c76c15e9f2d67006276" data-alt="{\displaystyle \odot }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  is the <a href="/wiki/Astronomical_symbols" title="Astronomical symbols">standard symbol</a> for the Sun, and <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \star }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo>⋆</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \star }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/bd316a21eeb5079a850f223b1d096a06bfa788c0" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: 0.035ex; margin-bottom: -0.206ex; width:1.162ex; height:1.509ex;" alt="{\displaystyle \star }"></noscript><span class="lazy-image-placeholder" style="width: 1.162ex;height: 1.509ex;vertical-align: 0.035ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/bd316a21eeb5079a850f223b1d096a06bfa788c0" data-alt="{\displaystyle \star }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  for a star (often omitted below). The unit often used for metallicity is the <a href="/wiki/Dex_(decimal_exponent)" title="Dex (decimal exponent)">dex</a>, contraction of "decimal exponent". By this formulation, stars with a higher metallicity than the Sun have a positive <a href="/wiki/Common_logarithm" title="Common logarithm">common logarithm</a>, whereas those more dominated by hydrogen have a corresponding negative value. For example, stars with a <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.2em" minsize="1.2em">[</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mfrac> </mstyle> </mrow> <msub> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.2em" minsize="1.2em">]</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mo>⋆</mo> </mrow> </msub> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/5392288ee560cfde9f1b75201a21e4d7bf1f6ec6" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.338ex; width:6.656ex; height:3.843ex;" alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }"></noscript><span class="lazy-image-placeholder" style="width: 6.656ex;height: 3.843ex;vertical-align: -1.338ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/5392288ee560cfde9f1b75201a21e4d7bf1f6ec6" data-alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  value of +1 have 10 times the metallicity of the Sun (10+1); conversely, those with a <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.2em" minsize="1.2em">[</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mfrac> </mstyle> </mrow> <msub> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.2em" minsize="1.2em">]</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mo>⋆</mo> </mrow> </msub> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/5392288ee560cfde9f1b75201a21e4d7bf1f6ec6" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.338ex; width:6.656ex; height:3.843ex;" alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }"></noscript><span class="lazy-image-placeholder" style="width: 6.656ex;height: 3.843ex;vertical-align: -1.338ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/5392288ee560cfde9f1b75201a21e4d7bf1f6ec6" data-alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  value of −1 have <style data-mw-deduplicate="TemplateStyles:r1214402035">.mw-parser-output .sfrac{white-space:nowrap}.mw-parser-output .sfrac.tion,.mw-parser-output .sfrac .tion{display:inline-block;vertical-align:-0.5em;font-size:85%;text-align:center}.mw-parser-output .sfrac .num{display:block;line-height:1em;margin:0.0em 0.1em;border-bottom:1px solid}.mw-parser-output .sfrac .den{display:block;line-height:1em;margin:0.1em 0.1em}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}</style>⁠1/10⁠, while those with a <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.2em" minsize="1.2em">[</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mfrac> </mstyle> </mrow> <msub> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.2em" minsize="1.2em">]</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mo>⋆</mo> </mrow> </msub> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/5392288ee560cfde9f1b75201a21e4d7bf1f6ec6" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.338ex; width:6.656ex; height:3.843ex;" alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }"></noscript><span class="lazy-image-placeholder" style="width: 6.656ex;height: 3.843ex;vertical-align: -1.338ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/5392288ee560cfde9f1b75201a21e4d7bf1f6ec6" data-alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}_{\star }\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  value of 0 have the same metallicity as the Sun, and so on.<a href="#cite_note-Martin-19">[19]</a> Young population I stars have significantly higher iron-to-hydrogen ratios than older population II stars. Primordial <a href="/wiki/Stellar_population#Population_III_stars" title="Stellar population">population III</a> stars are estimated to have metallicity less than −6, a millionth of the abundance of iron in the Sun.<a href="#cite_note-AJ-20150604-20">[20]</a><a href="#cite_note-NYT-20150617-21">[21]</a> The same notation is used to express variations in abundances between other individual elements as compared to solar proportions. For example, the notation <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {O}}{\mathsf {Fe}}}{\bigr ]}\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.2em" minsize="1.2em">[</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">O</mi> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> </mfrac> </mstyle> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.2em" minsize="1.2em">]</mo> </mrow> </mrow> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ {\bigl [}{\tfrac {\mathsf {O}}{\mathsf {Fe}}}{\bigr ]}\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/c015be8a2e9e300b36dfbb4dd5893bb879eefcfd" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.338ex; width:5.602ex; height:3.843ex;" alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {O}}{\mathsf {Fe}}}{\bigr ]}\ }"></noscript><span class="lazy-image-placeholder" style="width: 5.602ex;height: 3.843ex;vertical-align: -1.338ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/c015be8a2e9e300b36dfbb4dd5893bb879eefcfd" data-alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {O}}{\mathsf {Fe}}}{\bigr ]}\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  represents the difference in the logarithm of the star's oxygen abundance versus its iron content compared to that of the Sun. In general, a given <a href="/wiki/Stellar_nucleosynthesis" title="Stellar nucleosynthesis">stellar nucleosynthetic</a> process alters the proportions of only a few elements or isotopes, so a star or gas sample with certain <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {?}}{\mathsf {Fe}}}{\bigr ]}_{\star }\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.2em" minsize="1.2em">[</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mrow class="MJX-TeXAtom-ORD"> <mo mathvariant="sans-serif">?</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> </mfrac> </mstyle> </mrow> <msub> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.2em" minsize="1.2em">]</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mo>⋆</mo> </mrow> </msub> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ {\bigl [}{\tfrac {\mathsf {?}}{\mathsf {Fe}}}{\bigr ]}_{\star }\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b65d0d0ba6bf094444e4fa3ba7c5bf4d761e3b86" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.338ex; width:6.656ex; height:3.843ex;" alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {?}}{\mathsf {Fe}}}{\bigr ]}_{\star }\ }"></noscript><span class="lazy-image-placeholder" style="width: 6.656ex;height: 3.843ex;vertical-align: -1.338ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b65d0d0ba6bf094444e4fa3ba7c5bf4d761e3b86" data-alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {?}}{\mathsf {Fe}}}{\bigr ]}_{\star }\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  values may well be indicative of an associated, studied nuclear process. <div class="mw-heading mw-heading3"><h3 id="Photometric_colors">Photometric colors</h3> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=7" title="Edit section: Photometric colors" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div> Astronomers can estimate metallicities through measured and calibrated systems that correlate <a href="/wiki/Photometry_(astronomy)" title="Photometry (astronomy)">photometric measurements</a> and <a href="/wiki/Spectroscopy" title="Spectroscopy">spectroscopic measurements</a> (see also <a href="/wiki/Spectrophotometry" title="Spectrophotometry">Spectrophotometry</a>). For example, the <a href="/wiki/UBV_photometric_system" title="UBV photometric system">Johnson UVB filters</a> can be used to detect an <a href="/wiki/Ultraviolet" title="Ultraviolet">ultraviolet</a> (UV) excess in stars,<a href="#cite_note-22">[22]</a> where a smaller UV excess indicates a larger presence of metals that absorb the UV radiation, thereby making the star appear "redder".<a href="#cite_note-23">[23]</a><a href="#cite_note-24">[24]</a><a href="#cite_note-25">[25]</a> The UV excess, δ(U−B), is defined as the difference between a star's U and B band <a href="/wiki/Magnitude_(astronomy)" title="Magnitude (astronomy)">magnitudes</a>, compared to the difference between U and B band magnitudes of metal-rich stars in the <a href="/wiki/Hyades_(star_cluster)" title="Hyades (star cluster)">Hyades cluster</a>.<a href="#cite_note-Wildey-Burbidge-etal-1962-26">[26]</a> Unfortunately, δ(U−B) is sensitive to both metallicity and <a href="/wiki/Effective_temperature" title="Effective temperature">temperature</a>: If two stars are equally metal-rich, but one is cooler than the other, they will likely have different δ(U−B) values<a href="#cite_note-Wildey-Burbidge-etal-1962-26">[26]</a> (see also <a href="/wiki/Blanketing_effect" title="Blanketing effect">Blanketing effect</a><a href="#cite_note-27">[27]</a><a href="#cite_note-28">[28]</a>). To help mitigate this degeneracy, a star's B−V <a href="/wiki/Color_index" title="Color index">color index</a> can be used as an indicator for temperature. Furthermore, the UV excess and B−V index can be corrected to relate the δ(U−B) value to iron abundances.<a href="#cite_note-29">[29]</a><a href="#cite_note-30">[30]</a><a href="#cite_note-31">[31]</a> Other <a href="/wiki/Photometric_system" title="Photometric system">photometric systems</a> that can be used to determine metallicities of certain astrophysical objects include the Strӧmgren system,<a href="#cite_note-32">[32]</a><a href="#cite_note-33">[33]</a> the Geneva system,<a href="#cite_note-34">[34]</a><a href="#cite_note-35">[35]</a> the Washington system,<a href="#cite_note-36">[36]</a><a href="#cite_note-37">[37]</a> and the DDO system.<a href="#cite_note-38">[38]</a><a href="#cite_note-39">[39]</a> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(5)"><h2 id="Metallicities_in_various_astrophysical_objects">Metallicities in various astrophysical objects</h2> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=8" title="Edit section: Metallicities in various astrophysical objects" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div><section class="mf-section-5 collapsible-block" id="mf-section-5"> <div class="mw-heading mw-heading3"><h3 id="Stars">Stars</h3> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=9" title="Edit section: Stars" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div> At a given mass and age, a metal-poor star will be slightly warmer. <a href="/wiki/Population_II_star" class="mw-redirect" title="Population II star">Population II stars</a>' metallicities are roughly <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1214402035">⁠1/1000⁠ to <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1214402035">⁠1/10⁠ of the Sun's <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \left(\ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}\ ={-3.0}\ ...\ {-1.0}\ \right)\ ,}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mrow> <mo>(</mo> <mrow> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.2em" minsize="1.2em">[</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mfrac> </mstyle> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.2em" minsize="1.2em">]</mo> </mrow> </mrow> <mtext> </mtext> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mo>−</mo> <mn>3.0</mn> </mrow> <mtext> </mtext> <mo>.</mo> <mo>.</mo> <mo>.</mo> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mo>−</mo> <mn>1.0</mn> </mrow> <mtext> </mtext> </mrow> <mo>)</mo> </mrow> <mtext> </mtext> <mo>,</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \left(\ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}\ ={-3.0}\ ...\ {-1.0}\ \right)\ ,}</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/93d35c7995598257c64bab5a8654f8f97024aa48" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.838ex; width:27.494ex; height:4.843ex;" alt="{\displaystyle \left(\ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}\ ={-3.0}\ ...\ {-1.0}\ \right)\ ,}"></noscript><span class="lazy-image-placeholder" style="width: 27.494ex;height: 4.843ex;vertical-align: -1.838ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/93d35c7995598257c64bab5a8654f8f97024aa48" data-alt="{\displaystyle \left(\ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}\ ={-3.0}\ ...\ {-1.0}\ \right)\ ,}" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  but the group appears cooler than population I overall, as heavy population II stars have long since died. Above 40 <a href="/wiki/Solar_mass" title="Solar mass">solar masses</a>, metallicity influences how a star will die: Outside the <a href="/wiki/Pair-instability_supernova" title="Pair-instability supernova">pair-instability window</a>, lower metallicity stars will collapse directly to a black hole, while higher metallicity stars undergo a <a href="/wiki/Core-collapse_supernova" class="mw-redirect" title="Core-collapse supernova">type Ib/c supernova</a> and may leave a <a href="/wiki/Neutron_star" title="Neutron star">neutron star</a>. <div class="mw-heading mw-heading4"><h4 id="Relationship_between_stellar_metallicity_and_planets">Relationship between stellar metallicity and planets</h4> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=10" title="Edit section: Relationship between stellar metallicity and planets" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div> A star's metallicity measurement is one parameter that helps determine whether a star may have a giant <a href="/wiki/Planet" title="Planet">planet</a>, as there is a direct correlation between metallicity and the presence of a giant planet. Measurements have demonstrated the connection between a star's metallicity and <a href="/wiki/Gas_giant" title="Gas giant">gas giant</a> planets, like <a href="/wiki/Jupiter" title="Jupiter">Jupiter</a> and <a href="/wiki/Saturn" title="Saturn">Saturn</a>. The more metals in a star and thus its <a href="/wiki/Planetary_system" title="Planetary system">planetary system</a> and <a href="/wiki/Protoplanetary_disk" title="Protoplanetary disk">protoplanetary disk</a>, the more likely the system may have gas giant planets. Current models show that the metallicity along with the correct planetary system temperature and distance from the star are key to planet and <a href="/wiki/Planetesimal" title="Planetesimal">planetesimal</a> formation. For two stars that have equal age and mass but different metallicity, the less metallic star is <a href="/wiki/Stellar_classification" title="Stellar classification">bluer</a>. Among stars of the same color, less metallic stars emit more ultraviolet radiation. The Sun, with <a href="/wiki/Solar_System#Planets" title="Solar System">eight planets</a> and nine consensus <a href="/wiki/Dwarf_planets" class="mw-redirect" title="Dwarf planets">dwarf planets</a>, is used as the reference, with a <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.2em" minsize="1.2em">[</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">F</mi> <mi mathvariant="sans-serif">e</mi> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mfrac> </mstyle> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.2em" minsize="1.2em">]</mo> </mrow> </mrow> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/119adfa3ad9bd74448f8880ce03919f53a1b7b35" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.338ex; width:5.602ex; height:3.843ex;" alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}\ }"></noscript><span class="lazy-image-placeholder" style="width: 5.602ex;height: 3.843ex;vertical-align: -1.338ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/119adfa3ad9bd74448f8880ce03919f53a1b7b35" data-alt="{\displaystyle \ {\bigl [}{\tfrac {\mathsf {Fe}}{\mathsf {H}}}{\bigr ]}\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  of 0.00.<a href="#cite_note-40">[40]</a><a href="#cite_note-41">[41]</a><a href="#cite_note-42">[42]</a><a href="#cite_note-43">[43]</a><a href="#cite_note-44">[44]</a> <div class="mw-heading mw-heading4"><h4 id="HII_regions">HII regions</h4> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=11" title="Edit section: HII regions" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div> Young, massive and hot stars (typically of spectral types <a href="/wiki/O-type_star" title="O-type star">O</a> and <a href="/wiki/B-type_main-sequence_star" title="B-type main-sequence star">B</a>) in <a href="/wiki/H_II_region" title="H II region">HII regions</a> emit <a href="/wiki/Ultraviolet" title="Ultraviolet">UV photons</a> that ionize <a href="/wiki/Ground-state" class="mw-redirect" title="Ground-state">ground-state</a> hydrogen atoms, knocking <a href="/wiki/Electron" title="Electron">electrons</a> free; this process is known as <a href="/wiki/Photoionization" title="Photoionization">photoionization</a>. The free electrons can <a href="/wiki/Collisional_excitation" title="Collisional excitation">strike</a> other atoms nearby, exciting bound metallic electrons into a <a href="/wiki/Metastability" title="Metastability">metastable state</a>, which eventually decay back into a ground state, emitting photons with energies that correspond to <a href="/wiki/Forbidden_mechanism" title="Forbidden mechanism">forbidden lines</a>. Through these transitions, astronomers have developed several observational methods to estimate metal abundances in HII regions, where the stronger the forbidden lines in spectroscopic observations, the higher the metallicity.<a href="#cite_note-45">[45]</a><a href="#cite_note-46">[46]</a> These methods are dependent on one or more of the following: the variety of asymmetrical densities inside HII regions, the varied temperatures of the embedded stars, and/or the electron density within the ionized region.<a href="#cite_note-47">[47]</a><a href="#cite_note-48">[48]</a><a href="#cite_note-49">[49]</a><a href="#cite_note-50">[50]</a> Theoretically, to determine the total abundance of a single element in an HII region, all transition lines should be observed and summed. However, this can be observationally difficult due to variation in line strength.<a href="#cite_note-Grazyna-2004-Esteban-etal-51">[51]</a><a href="#cite_note-52">[52]</a> Some of the most common forbidden lines used to determine metal abundances in HII regions are from <a href="/wiki/Oxygen" title="Oxygen">oxygen</a> (e.g. [OII] λ = (3727, 7318, 7324) Å, and [OIII] λ = (4363, 4959, 5007) Å), <a href="/wiki/Nitrogen" title="Nitrogen">nitrogen</a> (e.g. [NII] λ = (5755, 6548, 6584) Å), and <a href="/wiki/Sulfur" title="Sulfur">sulfur</a> (e.g. [SII] λ = (6717, 6731) Å and [SIII] λ = (6312, 9069, 9531) Å) in the <a href="/wiki/Visible_spectrum" title="Visible spectrum">optical</a> spectrum, and the [OIII] λ = (52, 88) μm and [NIII] λ = 57 μm lines in the <a href="/wiki/Infrared_spectroscopy" title="Infrared spectroscopy">infrared</a> spectrum. <a href="/wiki/Oxygen" title="Oxygen">Oxygen</a> has some of the stronger, more abundant lines in HII regions, making it a main target for metallicity estimates within these objects. To calculate metal abundances in HII regions using oxygen <a href="/wiki/Flux" title="Flux">flux</a> measurements, astronomers often use the R23 method, in which <math display="block" xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle R_{23}={\frac {\ \left[\ {\mathsf {O}}^{\mathsf {II}}\right]_{3727~\mathrm {\AA} }+\left[\ {\mathsf {O}}^{\mathsf {III}}\right]_{4959~\mathrm {\AA} +5007~\mathrm {\AA} }\ }{{\Bigl [}\ {\mathsf {H}}_{\mathsf {\beta }}{\Bigr ]}_{4861~\mathrm {\AA} }}}\ ,}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>R</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>23</mn> </mrow> </msub> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mtext> </mtext> <msub> <mrow> <mo>[</mo> <mrow> <mtext> </mtext> <msup> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">O</mi> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> </mrow> </mrow> </msup> </mrow> <mo>]</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>3727</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> </mrow> </msub> <mo>+</mo> <msub> <mrow> <mo>[</mo> <mrow> <mtext> </mtext> <msup> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">O</mi> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> </mrow> </mrow> </msup> </mrow> <mo>]</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>4959</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> <mo>+</mo> <mn>5007</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> </mrow> </msub> <mtext> </mtext> </mrow> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.623em" minsize="1.623em">[</mo> </mrow> </mrow> <mtext> </mtext> <msub> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi>β</mi> </mrow> </mrow> </msub> <msub> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.623em" minsize="1.623em">]</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>4861</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> </mrow> </msub> </mrow> </mfrac> </mrow> <mtext> </mtext> <mo>,</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle R_{23}={\frac {\ \left[\ {\mathsf {O}}^{\mathsf {II}}\right]_{3727~\mathrm {\AA} }+\left[\ {\mathsf {O}}^{\mathsf {III}}\right]_{4959~\mathrm {\AA} +5007~\mathrm {\AA} }\ }{{\Bigl [}\ {\mathsf {H}}_{\mathsf {\beta }}{\Bigr ]}_{4861~\mathrm {\AA} }}}\ ,}</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/07da4c3a43ade348a36e361088a39a6b06399c9a" class="mwe-math-fallback-image-display mw-invert skin-invert" aria-hidden="true" style="vertical-align: -5.338ex; width:40.882ex; height:11.843ex;" alt="{\displaystyle R_{23}={\frac {\ \left[\ {\mathsf {O}}^{\mathsf {II}}\right]_{3727~\mathrm {\AA} }+\left[\ {\mathsf {O}}^{\mathsf {III}}\right]_{4959~\mathrm {\AA} +5007~\mathrm {\AA} }\ }{{\Bigl [}\ {\mathsf {H}}_{\mathsf {\beta }}{\Bigr ]}_{4861~\mathrm {\AA} }}}\ ,}"></noscript><span class="lazy-image-placeholder" style="width: 40.882ex;height: 11.843ex;vertical-align: -5.338ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/07da4c3a43ade348a36e361088a39a6b06399c9a" data-alt="{\displaystyle R_{23}={\frac {\ \left[\ {\mathsf {O}}^{\mathsf {II}}\right]_{3727~\mathrm {\AA} }+\left[\ {\mathsf {O}}^{\mathsf {III}}\right]_{4959~\mathrm {\AA} +5007~\mathrm {\AA} }\ }{{\Bigl [}\ {\mathsf {H}}_{\mathsf {\beta }}{\Bigr ]}_{4861~\mathrm {\AA} }}}\ ,}" data-class="mwe-math-fallback-image-display mw-invert skin-invert">  where <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \ \left[\ {\mathsf {O}}^{\mathsf {II}}\right]_{3727~\mathrm {\AA} }+\left[\ {\mathsf {O}}^{\mathsf {III}}\right]_{4959~\mathrm {\AA} +5007~\mathrm {\AA} }\ }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mtext> </mtext> <msub> <mrow> <mo>[</mo> <mrow> <mtext> </mtext> <msup> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">O</mi> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> </mrow> </mrow> </msup> </mrow> <mo>]</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>3727</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> </mrow> </msub> <mo>+</mo> <msub> <mrow> <mo>[</mo> <mrow> <mtext> </mtext> <msup> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">O</mi> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> </mrow> </mrow> </msup> </mrow> <mo>]</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>4959</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> <mo>+</mo> <mn>5007</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> </mrow> </msub> <mtext> </mtext> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \ \left[\ {\mathsf {O}}^{\mathsf {II}}\right]_{3727~\mathrm {\AA} }+\left[\ {\mathsf {O}}^{\mathsf {III}}\right]_{4959~\mathrm {\AA} +5007~\mathrm {\AA} }\ }</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/4f79eac8a49f97e36df6a877d73f986e76e9cc5d" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.505ex; width:32.079ex; height:5.509ex;" alt="{\displaystyle \ \left[\ {\mathsf {O}}^{\mathsf {II}}\right]_{3727~\mathrm {\AA} }+\left[\ {\mathsf {O}}^{\mathsf {III}}\right]_{4959~\mathrm {\AA} +5007~\mathrm {\AA} }\ }"></noscript><span class="lazy-image-placeholder" style="width: 32.079ex;height: 5.509ex;vertical-align: -2.505ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/4f79eac8a49f97e36df6a877d73f986e76e9cc5d" data-alt="{\displaystyle \ \left[\ {\mathsf {O}}^{\mathsf {II}}\right]_{3727~\mathrm {\AA} }+\left[\ {\mathsf {O}}^{\mathsf {III}}\right]_{4959~\mathrm {\AA} +5007~\mathrm {\AA} }\ }" data-class="mwe-math-fallback-image-inline mw-invert skin-invert">  is the sum of the fluxes from oxygen <a href="/wiki/Spectral_line" title="Spectral line">emission lines</a> measured at the <a href="/wiki/Rest_frame" title="Rest frame">rest frame</a> λ = (3727, 4959 and 5007) Å wavelengths, divided by the flux from the <a href="/wiki/Balmer_series" title="Balmer series">Balmer series</a> Hβ emission line at the rest frame λ = 4861 Å wavelength.<a href="#cite_note-53">[53]</a> This ratio is well defined through models and observational studies,<a href="#cite_note-54">[54]</a><a href="#cite_note-55">[55]</a><a href="#cite_note-56">[56]</a> but caution should be taken, as the ratio is often degenerate, providing both a low and high metallicity solution, which can be broken with additional line measurements.<a href="#cite_note-57">[57]</a> Similarly, other strong forbidden line ratios can be used, e.g. for sulfur, where<a href="#cite_note-58">[58]</a> <math display="block" xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle S_{23}={\frac {\ \left[\ {\mathsf {S}}^{\mathsf {II}}\right]_{6716~\mathrm {\AA} +6731~\mathrm {\AA} }+\left[\ {\mathsf {S}}^{\mathsf {III}}\right]_{9069~\mathrm {\AA} +9532~\mathrm {\AA} }\ }{{\Bigl [}\ {\mathsf {H}}_{\mathsf {\beta }}{\Bigr ]}_{4861~\mathrm {\AA} }}}~.}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>S</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>23</mn> </mrow> </msub> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mtext> </mtext> <msub> <mrow> <mo>[</mo> <mrow> <mtext> </mtext> <msup> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">S</mi> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> </mrow> </mrow> </msup> </mrow> <mo>]</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>6716</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> <mo>+</mo> <mn>6731</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> </mrow> </msub> <mo>+</mo> <msub> <mrow> <mo>[</mo> <mrow> <mtext> </mtext> <msup> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">S</mi> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> <mi mathvariant="sans-serif">I</mi> </mrow> </mrow> </msup> </mrow> <mo>]</mo> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>9069</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> <mo>+</mo> <mn>9532</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> </mrow> </msub> <mtext> </mtext> </mrow> <mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-OPEN"> <mo maxsize="1.623em" minsize="1.623em">[</mo> </mrow> </mrow> <mtext> </mtext> <msub> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi mathvariant="sans-serif">H</mi> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mi>β</mi> </mrow> </mrow> </msub> <msub> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-CLOSE"> <mo maxsize="1.623em" minsize="1.623em">]</mo> </mrow> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mn>4861</mn> <mtext> </mtext> <mrow class="MJX-TeXAtom-ORD"> <mrow class="MJX-TeXAtom-ORD"> <mo>Å</mo> </mrow> </mrow> </mrow> </msub> </mrow> </mfrac> </mrow> <mtext> </mtext> <mo>.</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle S_{23}={\frac {\ \left[\ {\mathsf {S}}^{\mathsf {II}}\right]_{6716~\mathrm {\AA} +6731~\mathrm {\AA} }+\left[\ {\mathsf {S}}^{\mathsf {III}}\right]_{9069~\mathrm {\AA} +9532~\mathrm {\AA} }\ }{{\Bigl [}\ {\mathsf {H}}_{\mathsf {\beta }}{\Bigr ]}_{4861~\mathrm {\AA} }}}~.}</annotation> </semantics> </math><noscript><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b89b407869c9ac2f28790cfd83fa17960c81f7e2" class="mwe-math-fallback-image-display mw-invert skin-invert" aria-hidden="true" style="vertical-align: -5.338ex; width:45.855ex; height:11.843ex;" alt="{\displaystyle S_{23}={\frac {\ \left[\ {\mathsf {S}}^{\mathsf {II}}\right]_{6716~\mathrm {\AA} +6731~\mathrm {\AA} }+\left[\ {\mathsf {S}}^{\mathsf {III}}\right]_{9069~\mathrm {\AA} +9532~\mathrm {\AA} }\ }{{\Bigl [}\ {\mathsf {H}}_{\mathsf {\beta }}{\Bigr ]}_{4861~\mathrm {\AA} }}}~.}"></noscript><span class="lazy-image-placeholder" style="width: 45.855ex;height: 11.843ex;vertical-align: -5.338ex;" data-src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b89b407869c9ac2f28790cfd83fa17960c81f7e2" data-alt="{\displaystyle S_{23}={\frac {\ \left[\ {\mathsf {S}}^{\mathsf {II}}\right]_{6716~\mathrm {\AA} +6731~\mathrm {\AA} }+\left[\ {\mathsf {S}}^{\mathsf {III}}\right]_{9069~\mathrm {\AA} +9532~\mathrm {\AA} }\ }{{\Bigl [}\ {\mathsf {H}}_{\mathsf {\beta }}{\Bigr ]}_{4861~\mathrm {\AA} }}}~.}" data-class="mwe-math-fallback-image-display mw-invert skin-invert">  Metal abundances within HII regions are typically less than 1%, with the percentage decreasing on average with distance from the <a href="/wiki/Galactic_Center" title="Galactic Center">Galactic Center</a>.<a href="#cite_note-Grazyna-2004-Esteban-etal-51">[51]</a><a href="#cite_note-59">[59]</a><a href="#cite_note-60">[60]</a><a href="#cite_note-61">[61]</a><a href="#cite_note-62">[62]</a> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(6)"><h2 id="See_also">See also</h2> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=12" title="Edit section: See also" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div><section class="mf-section-6 collapsible-block" id="mf-section-6"> <ul><li><a href="/wiki/Cosmos_Redshift_7" title="Cosmos Redshift 7">Cosmos Redshift 7</a>, a galaxy that reportedly contains Population III stars</li> <li><a href="/wiki/Galaxy_formation_and_evolution" title="Galaxy formation and evolution">Galaxy formation and evolution</a></li> <li><a href="/wiki/GRB_090423" title="GRB 090423">GRB 090423</a>, the most distant seen, presumably from a low-metallicity progenitor</li> <li><a href="/wiki/Metallicity_distribution_function" title="Metallicity distribution function">Metallicity distribution function</a></li></ul> <div style="clear:both;" class=""></div> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(7)"><h2 id="References">References</h2> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=13" title="Edit section: References" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div><section class="mf-section-7 collapsible-block" id="mf-section-7"> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width" style="column-width: 25em;"> <ol class="references"> <li id="cite_note-eb-1"><a href="#cite_ref-eb_1-0">^</a> Melvyn C. Usselman: <a rel="nofollow" class="external text" href="http://www.britannica.com/EBchecked/topic/646649/William-Hyde-Wollaston">William Hyde Wollaston</a> Encyclopædia Britannica, retrieved 31 March 2013 </li> <li id="cite_note-2"><a href="#cite_ref-2">^</a> William Hyde Wollaston (1802) <a rel="nofollow" class="external text" href="http://rstl.royalsocietypublishing.org/content/92/365.full.pdf+html">"A method of examining refractive and dispersive powers, by prismatic reflection,"</a> Philosophical Transactions of the Royal Society, 92: 365–380; see especially p. 378. </li> <li id="cite_note-3"><a href="#cite_ref-3">^</a> <style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFHearnshaw1986" class="citation book cs1">Hearnshaw, J.B. (1986). The analysis of starlight. Cambridge: <a href="/wiki/Cambridge_University_Press" title="Cambridge University Press">Cambridge University Press</a>. p. 27. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-521-39916-6" title="Special:BookSources/978-0-521-39916-6"><bdi>978-0-521-39916-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+analysis+of+starlight&rft.place=Cambridge&rft.pages=27&rft.pub=Cambridge+University+Press&rft.date=1986&rft.isbn=978-0-521-39916-6&rft.aulast=Hearnshaw&rft.aufirst=J.B.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-4"><a href="#cite_ref-4">^</a> Joseph Fraunhofer (1814 - 1815) <a rel="nofollow" class="external text" href="https://books.google.com/books?id=2-AAAAAAYAAJ&pg=PA203">"Bestimmung des Brechungs- und des Farben-Zerstreuungs - Vermögens verschiedener Glasarten, in Bezug auf die Vervollkommnung achromatischer Fernröhre"</a> (Determination of the refractive and color-dispersing power of different types of glass, in relation to the improvement of achromatic telescopes), Denkschriften der Königlichen Akademie der Wissenschaften zu München (Memoirs of the Royal Academy of Sciences in Munich), 5: 193–226; see especially pages 202–205 and the plate following page 226. </li> <li id="cite_note-5"><a href="#cite_ref-5">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJenkinsWhite1981" class="citation book cs1">Jenkins, Francis A.; White, Harvey E. (1981). <a rel="nofollow" class="external text" href="https://archive.org/details/fundamentalsopti00jenk">Fundamentals of Optics</a> (4th ed.). <a href="/wiki/McGraw-Hill" class="mw-redirect" title="McGraw-Hill">McGraw-Hill</a>. p. <a rel="nofollow" class="external text" href="https://archive.org/details/fundamentalsopti00jenk/page/n37">18</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-07-256191-3" title="Special:BookSources/978-0-07-256191-3"><bdi>978-0-07-256191-3</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Fundamentals+of+Optics&rft.pages=18&rft.edition=4th&rft.pub=McGraw-Hill&rft.date=1981&rft.isbn=978-0-07-256191-3&rft.aulast=Jenkins&rft.aufirst=Francis+A.&rft.au=White%2C+Harvey+E.&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Ffundamentalsopti00jenk&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-6"><a href="#cite_ref-6">^</a> See: <ul><li>Gustav Kirchhoff (1859) <a rel="nofollow" class="external text" href="https://books.google.com/books?id=CMgAAAAAYAAJ&pg=PA662">"Ueber die Fraunhofer'schen Linien"</a> (On Fraunhofer's lines), Monatsbericht der Königlichen Preussische Akademie der Wissenschaften zu Berlin (Monthly report of the Royal Prussian Academy of Sciences in Berlin), 662–665.</li> <li>Gustav Kirchhoff (1859) <a rel="nofollow" class="external text" href="https://books.google.com/books?id=uksDAAAAYAAJ&pg=RA1-PA251">"Ueber das Sonnenspektrum"</a> (On the sun's spectrum), Verhandlungen des naturhistorisch-medizinischen Vereins zu Heidelberg (Proceedings of the Natural History / Medical Association in Heidelberg), 1 (7) : 251–255.</li></ul> </li> <li id="cite_note-7"><a href="#cite_ref-7">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFG._Kirchhoff1860" class="citation journal cs1">G. Kirchhoff (1860). <a rel="nofollow" class="external text" href="https://zenodo.org/record/1423666">"Ueber die Fraunhofer'schen Linien"</a>. Annalen der Physik. 185 (1): 148–150. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1860AnP...185..148K">1860AnP...185..148K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fandp.18601850115">10.1002/andp.18601850115</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Annalen+der+Physik&rft.atitle=Ueber+die+Fraunhofer%27schen+Linien&rft.volume=185&rft.issue=1&rft.pages=148-150&rft.date=1860&rft_id=info%3Adoi%2F10.1002%2Fandp.18601850115&rft_id=info%3Abibcode%2F1860AnP...185..148K&rft.au=G.+Kirchhoff&rft_id=https%3A%2F%2Fzenodo.org%2Frecord%2F1423666&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-8"><a href="#cite_ref-8">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFG._Kirchhoff1860" class="citation journal cs1">G. Kirchhoff (1860). <a rel="nofollow" class="external text" href="https://zenodo.org/record/1423668">"Ueber das Verhältniss zwischen dem Emissionsvermögen und dem Absorptionsvermögen der Körper für Wärme und Licht"</a> [On the relation between the emissive power and the absorptive power of bodies towards heat and light]. Annalen der Physik. 185 (2): 275–301. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1860AnP...185..275K">1860AnP...185..275K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fandp.18601850205">10.1002/andp.18601850205</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Annalen+der+Physik&rft.atitle=Ueber+das+Verh%C3%A4ltniss+zwischen+dem+Emissionsverm%C3%B6gen+und+dem+Absorptionsverm%C3%B6gen+der+K%C3%B6rper+f%C3%BCr+W%C3%A4rme+und+Licht&rft.volume=185&rft.issue=2&rft.pages=275-301&rft.date=1860&rft_id=info%3Adoi%2F10.1002%2Fandp.18601850205&rft_id=info%3Abibcode%2F1860AnP...185..275K&rft.au=G.+Kirchhoff&rft_id=https%3A%2F%2Fzenodo.org%2Frecord%2F1423668&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-9"><a href="#cite_ref-9">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.chemteam.info/Chem-History/Kirchhoff-Bunsen-1860.html">"Kirchhoff and Bunsen on Spectroscopy"</a>. www.chemteam.info. Retrieved 2024-07-02.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.chemteam.info&rft.atitle=Kirchhoff+and+Bunsen+on+Spectroscopy&rft_id=https%3A%2F%2Fwww.chemteam.info%2FChem-History%2FKirchhoff-Bunsen-1860.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-10"><a href="#cite_ref-10">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://hdl.handle.net/2027/hvd.hn3317?urlappend=%3Bseq=211">"Spectrum analysis in its application to terrestrial substances and the physical constitution of the heavenly bodies : familiarly explained / by H. Schellen ..."</a> HathiTrust. <a href="/wiki/Hdl_(identifier)" class="mw-redirect" title="Hdl (identifier)">hdl</a>:<a rel="nofollow" class="external text" href="https://hdl.handle.net/2027%2Fhvd.hn3317?urlappend=%3Bseq=211">2027/hvd.hn3317</a>. Retrieved 2024-07-02.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=HathiTrust&rft.atitle=Spectrum+analysis+in+its+application+to+terrestrial+substances+and+the+physical+constitution+of+the+heavenly+bodies+%3A+familiarly+explained+%2F+by+H.+Schellen+...&rft_id=info%3Ahdl%2F2027%2Fhvd.hn3317%3Furlappend%3D%253Bseq%3D211&rft_id=https%3A%2F%2Fhdl.handle.net%2F2027%2Fhvd.hn3317%3Furlappend%3D%253Bseq%3D211&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-Meadows-11">^ <a href="#cite_ref-Meadows_11-0">a</a> <a href="#cite_ref-Meadows_11-1">b</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMeadows1970" class="citation book cs1">Meadows, A. J. (Arthur Jack) (1970). <a rel="nofollow" class="external text" href="http://archive.org/details/earlysolarphysic0000mead">Early solar physics</a>. Internet Archive. Oxford, New York, Pergamon Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-08-006653-0" title="Special:BookSources/978-0-08-006653-0"><bdi>978-0-08-006653-0</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Early+solar+physics&rft.pub=Oxford%2C+New+York%2C+Pergamon+Press&rft.date=1970&rft.isbn=978-0-08-006653-0&rft.aulast=Meadows&rft.aufirst=A.+J.+%28Arthur+Jack%29&rft_id=http%3A%2F%2Farchive.org%2Fdetails%2Fearlysolarphysic0000mead&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-12"><a href="#cite_ref-12">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBaade1944" class="citation journal cs1">Baade, Walter (1944). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F144650">"The Resolution of Messier 32, NGC 205, and the central region of the Andromeda Nebula"</a>. Astrophysical Journal. 100: 121–146. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1944ApJ...100..137B">1944ApJ...100..137B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F144650">10.1086/144650</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astrophysical+Journal&rft.atitle=The+Resolution+of+Messier+32%2C+NGC+205%2C+and+the+central+region+of+the+Andromeda+Nebula&rft.volume=100&rft.pages=121-146&rft.date=1944&rft_id=info%3Adoi%2F10.1086%2F144650&rft_id=info%3Abibcode%2F1944ApJ...100..137B&rft.aulast=Baade&rft.aufirst=Walter&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F144650&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-13"><a href="#cite_ref-13">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRees1978" class="citation journal cs1">Rees, M.J. (1978). "Origin of pregalactic microwave background". Nature. 275 (5675): 35–37. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1978Natur.275...35R">1978Natur.275...35R</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2F275035a0">10.1038/275035a0</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:121250998">121250998</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=Origin+of+pregalactic+microwave+background&rft.volume=275&rft.issue=5675&rft.pages=35-37&rft.date=1978&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A121250998%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1038%2F275035a0&rft_id=info%3Abibcode%2F1978Natur.275...35R&rft.aulast=Rees&rft.aufirst=M.J.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-14"><a href="#cite_ref-14">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWhiteRees1978" class="citation journal cs1">White, S.D.M.; Rees, M.J. (1978). <a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fmnras%2F183.3.341">"Core condensation in heavy halos - a two-stage theory for galaxy formation and clustering"</a>. Monthly Notices of the Royal Astronomical Society. 183 (3): 341–358. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1978MNRAS.183..341W">1978MNRAS.183..341W</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fmnras%2F183.3.341">10.1093/mnras/183.3.341</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Monthly+Notices+of+the+Royal+Astronomical+Society&rft.atitle=Core+condensation+in+heavy+halos+-+a+two-stage+theory+for+galaxy+formation+and+clustering&rft.volume=183&rft.issue=3&rft.pages=341-358&rft.date=1978&rft_id=info%3Adoi%2F10.1093%2Fmnras%2F183.3.341&rft_id=info%3Abibcode%2F1978MNRAS.183..341W&rft.aulast=White&rft.aufirst=S.D.M.&rft.au=Rees%2C+M.J.&rft_id=https%3A%2F%2Fdoi.org%2F10.1093%252Fmnras%252F183.3.341&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-15"><a href="#cite_ref-15">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPuget,_J.L.Heyvaerts,_J.1980" class="citation journal cs1">Puget, J.L.; Heyvaerts, J. (1980). "Population III stars and the shape of the cosmological black body radiation". Astronomy and Astrophysics. 83 (3): L10–L12. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1980A&A....83L..10P">1980A&A....83L..10P</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+and+Astrophysics&rft.atitle=Population+III+stars+and+the+shape+of+the+cosmological+black+body+radiation&rft.volume=83&rft.issue=3&rft.pages=L10-L12&rft.date=1980&rft_id=info%3Abibcode%2F1980A%26A....83L..10P&rft.au=Puget%2C+J.L.&rft.au=Heyvaerts%2C+J.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-asplund-16"><a href="#cite_ref-asplund_16-0">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAsplundGrevesseSauvalScott2009" class="citation journal cs1">Asplund, Martin; Grevesse, Nicolas; Sauval, A. Jacques; Scott, Pat (2009). "The chemical composition of the Sun". <a href="/wiki/Annual_Review_of_Astronomy_%26_Astrophysics" class="mw-redirect" title="Annual Review of Astronomy & Astrophysics">Annual Review of Astronomy & Astrophysics</a>. 47 (1): 481–522. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/0909.0948">0909.0948</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2009ARA&A..47..481A">2009ARA&A..47..481A</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1146%2Fannurev.astro.46.060407.145222">10.1146/annurev.astro.46.060407.145222</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:17921922">17921922</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Annual+Review+of+Astronomy+%26+Astrophysics&rft.atitle=The+chemical+composition+of+the+Sun&rft.volume=47&rft.issue=1&rft.pages=481-522&rft.date=2009&rft_id=info%3Aarxiv%2F0909.0948&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A17921922%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1146%2Fannurev.astro.46.060407.145222&rft_id=info%3Abibcode%2F2009ARA%26A..47..481A&rft.aulast=Asplund&rft.aufirst=Martin&rft.au=Grevesse%2C+Nicolas&rft.au=Sauval%2C+A.+Jacques&rft.au=Scott%2C+Pat&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-17"><a href="#cite_ref-17">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHinkelTimmesYoungPagano2014" class="citation journal cs1">Hinkel, Natalie; Timmes, Frank; Young, Patrick; Pagano, Michael; Turnbull, Maggie (September 2014). <a rel="nofollow" class="external text" href="https://iopscience.iop.org/article/10.1088/0004-6256/148/3/54">"Stellar abundances in the Solar neighborhood: The Hypatia Catalog"</a>. <a href="/wiki/Astronomical_Journal" class="mw-redirect" title="Astronomical Journal">Astronomical Journal</a>. 148 (3): 33. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/1405.6719">1405.6719</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2014AJ....148...54H">2014AJ....148...54H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1088%2F0004-6256%2F148%2F3%2F54">10.1088/0004-6256/148/3/54</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:119221402">119221402</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomical+Journal&rft.atitle=Stellar+abundances+in+the+Solar+neighborhood%3A+The+Hypatia+Catalog&rft.volume=148&rft.issue=3&rft.pages=33&rft.date=2014-09&rft_id=info%3Aarxiv%2F1405.6719&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A119221402%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1088%2F0004-6256%2F148%2F3%2F54&rft_id=info%3Abibcode%2F2014AJ....148...54H&rft.aulast=Hinkel&rft.aufirst=Natalie&rft.au=Timmes%2C+Frank&rft.au=Young%2C+Patrick&rft.au=Pagano%2C+Michael&rft.au=Turnbull%2C+Maggie&rft_id=https%3A%2F%2Fiopscience.iop.org%2Farticle%2F10.1088%2F0004-6256%2F148%2F3%2F54&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-Matteucci2001-18"><a href="#cite_ref-Matteucci2001_18-0">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMatteucci2001" class="citation book cs1">Matteucci, Francesca (2001). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=PT7O1nS7CksC&pg=PA7">The Chemical Evolution of the Galaxy</a>. Astrophysics and Space Science Library. Vol. 253. Springer Science & Business Media. p. 7. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-7923-6552-5" title="Special:BookSources/978-0-7923-6552-5"><bdi>978-0-7923-6552-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Chemical+Evolution+of+the+Galaxy&rft.series=Astrophysics+and+Space+Science+Library&rft.pages=7&rft.pub=Springer+Science+%26+Business+Media&rft.date=2001&rft.isbn=978-0-7923-6552-5&rft.aulast=Matteucci&rft.aufirst=Francesca&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DPT7O1nS7CksC%26pg%3DPA7&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-Martin-19"><a href="#cite_ref-Martin_19-0">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMartin,_John_C." class="citation web cs1">Martin, John C. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20141009051221/https://edocs.uis.edu/jmart5/www/rrlyrae/metals.htm">"What we learn from a star's metal content"</a>. New analysis RR Lyrae kinematics in the solar neighborhood. <a href="/wiki/University_of_Illinois,_Springfield" class="mw-redirect" title="University of Illinois, Springfield">University of Illinois, Springfield</a>. Archived from <a rel="nofollow" class="external text" href="https://edocs.uis.edu/jmart5/www/rrlyrae/metals.htm">the original</a> on 2014-10-09. Retrieved 7 September 2005.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=What+we+learn+from+a+star%27s+metal+content&rft.series=New+analysis+RR+Lyrae+kinematics+in+the+solar+neighborhood&rft.pub=University+of+Illinois%2C+Springfield&rft.au=Martin%2C+John+C.&rft_id=https%3A%2F%2Fedocs.uis.edu%2Fjmart5%2Fwww%2Frrlyrae%2Fmetals.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-AJ-20150604-20"><a href="#cite_ref-AJ-20150604_20-0">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSobralMattheeDarvishSchaerer2015" class="citation journal cs1">Sobral, David; Matthee, Jorryt; Darvish, Behnam; Schaerer, Daniel; Mobasher, Bahram; Röttgering, Huub J.A.; et al. (4 June 2015). "Evidence for pop III-like stellar populations in the most luminous Lyman-α emitters at the epoch of re-ionisation: Spectroscopic confirmation". <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 808 (2): 139. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/1504.01734">1504.01734</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2015ApJ...808..139S">2015ApJ...808..139S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1088%2F0004-637x%2F808%2F2%2F139">10.1088/0004-637x/808/2/139</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:18471887">18471887</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Evidence+for+pop+III-like+stellar+populations+in+the+most+luminous+Lyman-%CE%B1+emitters+at+the+epoch+of+re-ionisation%3A+Spectroscopic+confirmation&rft.volume=808&rft.issue=2&rft.pages=139&rft.date=2015-06-04&rft_id=info%3Aarxiv%2F1504.01734&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A18471887%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1088%2F0004-637x%2F808%2F2%2F139&rft_id=info%3Abibcode%2F2015ApJ...808..139S&rft.aulast=Sobral&rft.aufirst=David&rft.au=Matthee%2C+Jorryt&rft.au=Darvish%2C+Behnam&rft.au=Schaerer%2C+Daniel&rft.au=Mobasher%2C+Bahram&rft.au=R%C3%B6ttgering%2C+Huub+J.A.&rft.au=Santos%2C+S%C3%A9rgio&rft.au=Hemmati%2C+Shoubaneh&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-NYT-20150617-21"><a href="#cite_ref-NYT-20150617_21-0">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFOverbye2015" class="citation news cs1"><a href="/wiki/Dennis_Overbye" title="Dennis Overbye">Overbye, Dennis</a> (17 June 2015). <a rel="nofollow" class="external text" href="https://www.nytimes.com/2015/06/18/science/space/astronomers-report-finding-earliest-stars-that-enriched-cosmos.html">"Astronomers report finding earliest stars that enriched the cosmos"</a>. <a href="/wiki/The_New_York_Times" title="The New York Times">The New York Times</a>. Retrieved 17 June 2015.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=Astronomers+report+finding+earliest+stars+that+enriched+the+cosmos&rft.date=2015-06-17&rft.aulast=Overbye&rft.aufirst=Dennis&rft_id=https%3A%2F%2Fwww.nytimes.com%2F2015%2F06%2F18%2Fscience%2Fspace%2Fastronomers-report-finding-earliest-stars-that-enriched-cosmos.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-22"><a href="#cite_ref-22">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJohnsonMorgan1953" class="citation journal cs1">Johnson, H.L.; Morgan, W.W. (May 1953). "Fundamental stellar photometry for standards of spectral type on the revised system of the Yerkes Spectral Atlas". <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 117: 313. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1953ApJ...117..313J">1953ApJ...117..313J</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F145697">10.1086/145697</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Fundamental+stellar+photometry+for+standards+of+spectral+type+on+the+revised+system+of+the+Yerkes+Spectral+Atlas&rft.volume=117&rft.pages=313&rft.date=1953-05&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F145697&rft_id=info%3Abibcode%2F1953ApJ...117..313J&rft.aulast=Johnson&rft.aufirst=H.L.&rft.au=Morgan%2C+W.W.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-23"><a href="#cite_ref-23">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRoman1955" class="citation journal cs1">Roman, Nancy G. (December 1955). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F190021">"A catalogue of high-velocity stars"</a>. The Astrophysical Journal Supplement Series. 2: 195. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1955ApJS....2..195R">1955ApJS....2..195R</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F190021">10.1086/190021</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0067-0049">0067-0049</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal+Supplement+Series&rft.atitle=A+catalogue+of+high-velocity+stars&rft.volume=2&rft.pages=195&rft.date=1955-12&rft.issn=0067-0049&rft_id=info%3Adoi%2F10.1086%2F190021&rft_id=info%3Abibcode%2F1955ApJS....2..195R&rft.aulast=Roman&rft.aufirst=Nancy+G.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F190021&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-24"><a href="#cite_ref-24">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSandageEggen1959" class="citation journal cs1"><a href="/wiki/Allan_Sandage" title="Allan Sandage">Sandage, A.R.</a>; Eggen, O.J. (1959-06-01). <a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fmnras%2F119.3.278">"On the existence of subdwarfs in the (MBol, log Te)-diagram"</a>. <a href="/wiki/Monthly_Notices_of_the_Royal_Astronomical_Society" title="Monthly Notices of the Royal Astronomical Society">Monthly Notices of the Royal Astronomical Society</a>. 119 (3): 278–296. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1959MNRAS.119..278S">1959MNRAS.119..278S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fmnras%2F119.3.278">10.1093/mnras/119.3.278</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0035-8711">0035-8711</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Monthly+Notices+of+the+Royal+Astronomical+Society&rft.atitle=On+the+existence+of+subdwarfs+in+the+%28MBol%2C+log+Te%29-diagram&rft.volume=119&rft.issue=3&rft.pages=278-296&rft.date=1959-06-01&rft.issn=0035-8711&rft_id=info%3Adoi%2F10.1093%2Fmnras%2F119.3.278&rft_id=info%3Abibcode%2F1959MNRAS.119..278S&rft.aulast=Sandage&rft.aufirst=A.R.&rft.au=Eggen%2C+O.J.&rft_id=https%3A%2F%2Fdoi.org%2F10.1093%252Fmnras%252F119.3.278&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-25"><a href="#cite_ref-25">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWallersteinCarlson1960" class="citation journal cs1">Wallerstein, George; Carlson, Maurice (September 1960). "Letter to the Editor: On the ultraviolet excess in G dwarfs". <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 132: 276. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1960ApJ...132..276W">1960ApJ...132..276W</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F146926">10.1086/146926</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Letter+to+the+Editor%3A+On+the+ultraviolet+excess+in+G+dwarfs&rft.volume=132&rft.pages=276&rft.date=1960-09&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F146926&rft_id=info%3Abibcode%2F1960ApJ...132..276W&rft.aulast=Wallerstein&rft.aufirst=George&rft.au=Carlson%2C+Maurice&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-Wildey-Burbidge-etal-1962-26">^ <a href="#cite_ref-Wildey-Burbidge-etal-1962_26-0">a</a> <a href="#cite_ref-Wildey-Burbidge-etal-1962_26-1">b</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWildeyBurbidgeSandageBurbidge1962" class="citation journal cs1">Wildey, R.L.; Burbidge, E.M.; <a href="/wiki/Allan_Sandage" title="Allan Sandage">Sandage, A.R.</a>; Burbidge, G.R. (January 1962). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F147251">"On the effect of Fraunhofer lines on u, b, V measurements"</a>. <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 135: 94. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1962ApJ...135...94W">1962ApJ...135...94W</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F147251">10.1086/147251</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=On+the+effect+of+Fraunhofer+lines+on+u%2C+b%2C+V+measurements&rft.volume=135&rft.pages=94&rft.date=1962-01&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F147251&rft_id=info%3Abibcode%2F1962ApJ...135...94W&rft.aulast=Wildey&rft.aufirst=R.L.&rft.au=Burbidge%2C+E.M.&rft.au=Sandage%2C+A.R.&rft.au=Burbidge%2C+G.R.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F147251&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-27"><a href="#cite_ref-27">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSchwarzschildSearleHoward1955" class="citation journal cs1">Schwarzschild, M.; Searle, L.; Howard, R. (September 1955). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F146094">"On the colors of subdwarfs"</a>. <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 122: 353. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1955ApJ...122..353S">1955ApJ...122..353S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F146094">10.1086/146094</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=On+the+colors+of+subdwarfs&rft.volume=122&rft.pages=353&rft.date=1955-09&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F146094&rft_id=info%3Abibcode%2F1955ApJ...122..353S&rft.aulast=Schwarzschild&rft.aufirst=M.&rft.au=Searle%2C+L.&rft.au=Howard%2C+R.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F146094&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-28"><a href="#cite_ref-28">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCameron1985" class="citation journal cs1">Cameron, L. M. (June 1985). "Metallicities and distances of galactic clusters as determined from UBV data – Part Three – Ages and abundance gradients of open clusters". <a href="/wiki/Astronomy_and_Astrophysics" class="mw-redirect" title="Astronomy and Astrophysics">Astronomy and Astrophysics</a>. 147: 47. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1985A&A...147...47C">1985A&A...147...47C</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-6361">0004-6361</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+and+Astrophysics&rft.atitle=Metallicities+and+distances+of+galactic+clusters+as+determined+from+UBV+data+%E2%80%93+Part+Three+%E2%80%93+Ages+and+abundance+gradients+of+open+clusters&rft.volume=147&rft.pages=47&rft.date=1985-06&rft.issn=0004-6361&rft_id=info%3Abibcode%2F1985A%26A...147...47C&rft.aulast=Cameron&rft.aufirst=L.+M.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-29"><a href="#cite_ref-29">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSandage1969" class="citation journal cs1"><a href="/wiki/Allan_Sandage" title="Allan Sandage">Sandage, A.R.</a> (December 1969). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F150271">"New subdwarfs. II. Radial velocities, photometry, and preliminary space motions for 112 stars with large proper motion"</a>. <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 158: 1115. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1969ApJ...158.1115S">1969ApJ...158.1115S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F150271">10.1086/150271</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=New+subdwarfs.+II.+Radial+velocities%2C+photometry%2C+and+preliminary+space+motions+for+112+stars+with+large+proper+motion&rft.volume=158&rft.pages=1115&rft.date=1969-12&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F150271&rft_id=info%3Abibcode%2F1969ApJ...158.1115S&rft.aulast=Sandage&rft.aufirst=A.R.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F150271&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-30"><a href="#cite_ref-30">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCarney1979" class="citation journal cs1">Carney, B.W. (October 1979). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F157383">"Subdwarf ultraviolet excesses and metal abundances"</a>. <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 233: 211. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1979ApJ...233..211C">1979ApJ...233..211C</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F157383">10.1086/157383</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Subdwarf+ultraviolet+excesses+and+metal+abundances&rft.volume=233&rft.pages=211&rft.date=1979-10&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F157383&rft_id=info%3Abibcode%2F1979ApJ...233..211C&rft.aulast=Carney&rft.aufirst=B.W.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F157383&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-31"><a href="#cite_ref-31">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLairdCarneyLatham1988" class="citation journal cs1">Laird, John B.; Carney, Bruce W.; Latham, David W. (June 1988). "A survey of proper-motion stars. III - Reddenings, distances, and metallicities". <a href="/wiki/The_Astronomical_Journal" title="The Astronomical Journal">The Astronomical Journal</a>. 95: 1843. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1988AJ.....95.1843L">1988AJ.....95.1843L</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F114782">10.1086/114782</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-6256">0004-6256</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astronomical+Journal&rft.atitle=A+survey+of+proper-motion+stars.+III+-+Reddenings%2C+distances%2C+and+metallicities&rft.volume=95&rft.pages=1843&rft.date=1988-06&rft.issn=0004-6256&rft_id=info%3Adoi%2F10.1086%2F114782&rft_id=info%3Abibcode%2F1988AJ.....95.1843L&rft.aulast=Laird&rft.aufirst=John+B.&rft.au=Carney%2C+Bruce+W.&rft.au=Latham%2C+David+W.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-32"><a href="#cite_ref-32">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFStrömgren1963" class="citation book cs1">Strömgren, Bengt (1963). "Quantitative classification methods". In Strand, Kaj Aage (ed.). Basic Astronomical Data: Stars and stellar systems (original (re-issued 1968) ed.). Chicago, IL: University of Chicago Press. p. 123. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1963bad..book..123S">1963bad..book..123S</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Quantitative+classification+methods&rft.btitle=Basic+Astronomical+Data%3A+Stars+and+stellar+systems&rft.place=Chicago%2C+IL&rft.pages=123&rft.edition=original+%28re-issued+1968%29&rft.pub=University+of+Chicago+Press&rft.date=1963&rft_id=info%3Abibcode%2F1963bad..book..123S&rft.aulast=Str%C3%B6mgren&rft.aufirst=Bengt&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> <ul><li>1980 reprint edition: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/OCLC_(identifier)" class="mw-redirect" title="OCLC (identifier)">OCLC</a> <a rel="nofollow" class="external text" href="https://www.worldcat.org/oclc/7047642">7047642</a>, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-2264-5964-0" title="Special:BookSources/0-2264-5964-0">0-2264-5964-0</a></li> <li>1988 reprint edition: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-2-2645-9640-6" title="Special:BookSources/978-2-2645-9640-6">978-2-2645-9640-6</a></li></ul> </li> <li id="cite_note-33"><a href="#cite_ref-33">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCrawford1966" class="citation journal cs1">Crawford, L.D. (1966). "Photo-electric H-beta and U V B Y photometry". Spectral Classification and Multicolour Photometry. 24: 170. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1966IAUS...24..170C">1966IAUS...24..170C</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Spectral+Classification+and+Multicolour+Photometry&rft.atitle=Photo-electric+H-beta+and+U+V+B+Y+photometry&rft.volume=24&rft.pages=170&rft.date=1966&rft_id=info%3Abibcode%2F1966IAUS...24..170C&rft.aulast=Crawford&rft.aufirst=L.D.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-34"><a href="#cite_ref-34">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFCramerMaeder1979" class="citation journal cs1">Cramer, N.; Maeder, A. (October 1979). "Luminosity and Teff determinations for B-type stars". Astronomy and Astrophysics. 78: 305. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1979A&A....78..305C">1979A&A....78..305C</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-6361">0004-6361</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+and+Astrophysics&rft.atitle=Luminosity+and+%3Cspan+class%3D%22texhtml+mvar%22+style%3D%22font-style%3Aitalic%3B%22%3ET%3C%2Fspan%3E%3Csub%3Eeff%3C%2Fsub%3E+determinations+for+B-type+stars&rft.volume=78&rft.pages=305&rft.date=1979-10&rft.issn=0004-6361&rft_id=info%3Abibcode%2F1979A%26A....78..305C&rft.aulast=Cramer&rft.aufirst=N.&rft.au=Maeder%2C+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-35"><a href="#cite_ref-35">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKobiNorth1990" class="citation journal cs1">Kobi, D.; North, P. (November 1990). "A new calibration of the Geneva photometry in terms of Te, log g, (Fe/H) and mass for main sequence A4 to G5 stars". Astronomy and Astrophysics Supplement Series. 85: 999. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1990A&AS...85..999K">1990A&AS...85..999K</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0365-0138">0365-0138</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+and+Astrophysics+Supplement+Series&rft.atitle=A+new+calibration+of+the+Geneva+photometry+in+terms+of+Te%2C+log+g%2C+%28Fe%2FH%29+and+mass+for+main+sequence+A4+to+G5+stars&rft.volume=85&rft.pages=999&rft.date=1990-11&rft.issn=0365-0138&rft_id=info%3Abibcode%2F1990A%26AS...85..999K&rft.aulast=Kobi&rft.aufirst=D.&rft.au=North%2C+P.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-36"><a href="#cite_ref-36">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGeisler1986" class="citation journal cs1">Geisler, D. (1986). <a rel="nofollow" class="external text" href="http://stacks.iop.org/1538-3873/98/i=606/a=762">"The empirical abundance calibrations for Washington photometry of population II giants"</a>. Publications of the Astronomical Society of the Pacific. 98 (606): 762. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1986PASP...98..762G">1986PASP...98..762G</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F131822">10.1086/131822</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1538-3873">1538-3873</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Publications+of+the+Astronomical+Society+of+the+Pacific&rft.atitle=The+empirical+abundance+calibrations+for+Washington+photometry+of+population+II+giants&rft.volume=98&rft.issue=606&rft.pages=762&rft.date=1986&rft.issn=1538-3873&rft_id=info%3Adoi%2F10.1086%2F131822&rft_id=info%3Abibcode%2F1986PASP...98..762G&rft.aulast=Geisler&rft.aufirst=D.&rft_id=http%3A%2F%2Fstacks.iop.org%2F1538-3873%2F98%2Fi%3D606%2Fa%3D762&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-37"><a href="#cite_ref-37">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGeislerClariaMinniti1991" class="citation journal cs1">Geisler, Doug; Claria, Juan J.; Minniti, Dante (November 1991). "An improved metal abundance calibration for the Washington system". The Astronomical Journal. 102: 1836. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1991AJ....102.1836G">1991AJ....102.1836G</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F116008">10.1086/116008</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-6256">0004-6256</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astronomical+Journal&rft.atitle=An+improved+metal+abundance+calibration+for+the+Washington+system&rft.volume=102&rft.pages=1836&rft.date=1991-11&rft.issn=0004-6256&rft_id=info%3Adoi%2F10.1086%2F116008&rft_id=info%3Abibcode%2F1991AJ....102.1836G&rft.aulast=Geisler&rft.aufirst=Doug&rft.au=Claria%2C+Juan+J.&rft.au=Minniti%2C+Dante&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-38"><a href="#cite_ref-38">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFClariaPiattiLapasset1994" class="citation journal cs1">Claria, Juan J.; Piatti, Andres E.; Lapasset, Emilio (May 1994). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F133398">"A revised effective-temperature calibration for the DDO photometric system"</a>. Publications of the Astronomical Society of the Pacific. 106: 436. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1994PASP..106..436C">1994PASP..106..436C</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F133398">10.1086/133398</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-6280">0004-6280</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Publications+of+the+Astronomical+Society+of+the+Pacific&rft.atitle=A+revised+effective-temperature+calibration+for+the+DDO+photometric+system&rft.volume=106&rft.pages=436&rft.date=1994-05&rft.issn=0004-6280&rft_id=info%3Adoi%2F10.1086%2F133398&rft_id=info%3Abibcode%2F1994PASP..106..436C&rft.aulast=Claria&rft.aufirst=Juan+J.&rft.au=Piatti%2C+Andres+E.&rft.au=Lapasset%2C+Emilio&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F133398&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-39"><a href="#cite_ref-39">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJames1975" class="citation journal cs1">James, K.A. (May 1975). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F190339">"Cyanogen strengths, luminosities, and kinematics of K giant stars"</a>. The Astrophysical Journal Supplement Series. 29: 161. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1975ApJS...29..161J">1975ApJS...29..161J</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F190339">10.1086/190339</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0067-0049">0067-0049</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal+Supplement+Series&rft.atitle=Cyanogen+strengths%2C+luminosities%2C+and+kinematics+of+K+giant+stars&rft.volume=29&rft.pages=161&rft.date=1975-05&rft.issn=0067-0049&rft_id=info%3Adoi%2F10.1086%2F190339&rft_id=info%3Abibcode%2F1975ApJS...29..161J&rft.aulast=James&rft.aufirst=K.A.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F190339&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-40"><a href="#cite_ref-40">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWang" class="citation web cs1">Wang, Ji. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20170713073323/http://www.astro.caltech.edu/~jwang/Project4.html">"Planet-metallicity correlation - the rich get richer"</a>. <a href="/wiki/Caltech" class="mw-redirect" title="Caltech">Caltech</a>. Archived from <a rel="nofollow" class="external text" href="http://www.astro.caltech.edu/~jwang/Project4.html">the original</a> on 2017-07-13. Retrieved 2016-09-28.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Planet-metallicity+correlation+-+the+rich+get+richer&rft.pub=Caltech&rft.aulast=Wang&rft.aufirst=Ji&rft_id=http%3A%2F%2Fwww.astro.caltech.edu%2F~jwang%2FProject4.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-41"><a href="#cite_ref-41">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFischerValenti2005" class="citation journal cs1">Fischer, Debra A.; Valenti, Jeff (2005). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F428383">"The planet-metallicity correlation"</a>. <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 622 (2): 1102. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2005ApJ...622.1102F">2005ApJ...622.1102F</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F428383">10.1086/428383</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=The+planet-metallicity+correlation&rft.volume=622&rft.issue=2&rft.pages=1102&rft.date=2005&rft_id=info%3Adoi%2F10.1086%2F428383&rft_id=info%3Abibcode%2F2005ApJ...622.1102F&rft.aulast=Fischer&rft.aufirst=Debra+A.&rft.au=Valenti%2C+Jeff&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F428383&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-42"><a href="#cite_ref-42">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWangFischer2013" class="citation journal cs1">Wang, Ji; Fischer, Debra A. (2013). "Revealing a universal planet-metallicity correlation for planets of different sizes around Solar-type stars". <a href="/wiki/The_Astronomical_Journal" title="The Astronomical Journal">The Astronomical Journal</a>. 149 (1): 14. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/1310.7830">1310.7830</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2015AJ....149...14W">2015AJ....149...14W</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1088%2F0004-6256%2F149%2F1%2F14">10.1088/0004-6256/149/1/14</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:118415186">118415186</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astronomical+Journal&rft.atitle=Revealing+a+universal+planet-metallicity+correlation+for+planets+of+different+sizes+around+Solar-type+stars&rft.volume=149&rft.issue=1&rft.pages=14&rft.date=2013&rft_id=info%3Aarxiv%2F1310.7830&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A118415186%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1088%2F0004-6256%2F149%2F1%2F14&rft_id=info%3Abibcode%2F2015AJ....149...14W&rft.aulast=Wang&rft.aufirst=Ji&rft.au=Fischer%2C+Debra+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-43"><a href="#cite_ref-43">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSanders,_Ray2012" class="citation magazine cs1">Sanders, Ray (9 April 2012). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20210507132606/https://www.astrobio.net/news-exclusive/when-stellar-metallicity-sparks-planet-formation/">"When stellar metallicity sparks planet formation"</a>. Astrobiology Magazine. Archived from <a rel="nofollow" class="external text" href="http://www.astrobio.net/news-exclusive/when-stellar-metallicity-sparks-planet-formation/">the original</a> on 2021-05-07.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astrobiology+Magazine&rft.atitle=When+stellar+metallicity+sparks+planet+formation&rft.date=2012-04-09&rft.au=Sanders%2C+Ray&rft_id=http%3A%2F%2Fwww.astrobio.net%2Fnews-exclusive%2Fwhen-stellar-metallicity-sparks-planet-formation%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-44"><a href="#cite_ref-44">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHill,_VanessaFrançois,_PatrickPrimas,_Francesca" class="citation conference cs1">Hill, Vanessa; François, Patrick; <a href="/wiki/Francesca_Primas" title="Francesca Primas">Primas, Francesca</a> (eds.). "The G star problem". From Lithium to Uranium: Elemental tracers of early cosmic evolution. <a href="/wiki/International_Astronomical_Union" title="International Astronomical Union">IAU</a> Symposium 228. Proceedings of the <a href="/wiki/International_Astronomical_Union" title="International Astronomical Union">International Astronomical Union</a> Symposia and Colloquia. Vol. 228. pp. 509–511.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=conference&rft.atitle=The+G+star+problem&rft.btitle=From+Lithium+to+Uranium%3A+Elemental+tracers+of+early+cosmic+evolution&rft.series=Proceedings+of+the+International+Astronomical+Union+Symposia+and+Colloquia&rft.pages=509-511&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> [<a href="/wiki/Template:Harvard_citation_documentation#Wikilink_to_citation_does_not_work" title="Template:Harvard citation documentation">citation not found</a>] <dl><dd>Missing article's page numbers are imbedded in:</dd></dl> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFArimoto,_N.2005" class="citation conference cs1">Arimoto, N. (23–27 May 2005). "Linking the halo to its surroundings". In Hill, Vanessa; François, Patrick; <a href="/wiki/Francesca_Primas" title="Francesca Primas">Primas, Francesca</a> (eds.). From Lithium to Uranium: Elemental tracers of early cosmic evolution. <a href="/wiki/International_Astronomical_Union" title="International Astronomical Union">IAU</a> Symposium 228. Proceedings of the <a href="/wiki/International_Astronomical_Union" title="International Astronomical Union">International Astronomical Union</a> Symposia and Colloquia. Vol. 228. Paris, France: <a href="/wiki/International_Astronomical_Union" title="International Astronomical Union">IAU</a> / Cambridge University Press (published February 2006). pp. 503–512. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2005IAUS..228..503A">2005IAUS..228..503A</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1017%2FS1743921305006344">10.1017/S1743921305006344</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-52185199-2" title="Special:BookSources/978-0-52185199-2"><bdi>978-0-52185199-2</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=conference&rft.atitle=Linking+the+halo+to+its+surroundings&rft.btitle=From+Lithium+to+Uranium%3A+Elemental+tracers+of+early+cosmic+evolution&rft.place=Paris%2C+France&rft.series=Proceedings+of+the+International+Astronomical+Union+Symposia+and+Colloquia&rft.pages=503-512&rft.pub=IAU+%2F+Cambridge+University+Press&rft.date=2005-05-23%2F2005-05-27&rft_id=info%3Adoi%2F10.1017%2FS1743921305006344&rft_id=info%3Abibcode%2F2005IAUS..228..503A&rft.isbn=978-0-52185199-2&rft.au=Arimoto%2C+N.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-45"><a href="#cite_ref-45">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKewleyDopita2002" class="citation journal cs1">Kewley, L.J.; Dopita, M.A. (September 2002). "Using strong lines to estimate abundances in extragalactic HII regions and starburst galaxies". The Astrophysical Journal Supplement Series. 142 (1): 35–52. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/0206495">astro-ph/0206495</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2002ApJS..142...35K">2002ApJS..142...35K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F341326">10.1086/341326</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0067-0049">0067-0049</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:16655590">16655590</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal+Supplement+Series&rft.atitle=Using+strong+lines+to+estimate+abundances+in+extragalactic+H%3Csup%3EII%3C%2Fsup%3E+regions+and+starburst+galaxies&rft.volume=142&rft.issue=1&rft.pages=35-52&rft.date=2002-09&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A16655590%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2002ApJS..142...35K&rft_id=info%3Aarxiv%2Fastro-ph%2F0206495&rft.issn=0067-0049&rft_id=info%3Adoi%2F10.1086%2F341326&rft.aulast=Kewley&rft.aufirst=L.J.&rft.au=Dopita%2C+M.A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-46"><a href="#cite_ref-46">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFNagaoMaiolinoMarconi2006" class="citation journal cs1">Nagao, T.; Maiolino, R.; Marconi, A. (2006-09-12). "Gas metallicity diagnostics in star-forming galaxies". <a href="/wiki/Astronomy_%26_Astrophysics" title="Astronomy & Astrophysics">Astronomy & Astrophysics</a>. 459 (1): 85–101. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/0603580">astro-ph/0603580</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2006A&A...459...85N">2006A&A...459...85N</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1051%2F0004-6361%3A20065216">10.1051/0004-6361:20065216</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-6361">0004-6361</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:16220272">16220272</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+%26+Astrophysics&rft.atitle=Gas+metallicity+diagnostics+in+star-forming+galaxies&rft.volume=459&rft.issue=1&rft.pages=85-101&rft.date=2006-09-12&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A16220272%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2006A%26A...459...85N&rft_id=info%3Aarxiv%2Fastro-ph%2F0603580&rft.issn=0004-6361&rft_id=info%3Adoi%2F10.1051%2F0004-6361%3A20065216&rft.aulast=Nagao&rft.aufirst=T.&rft.au=Maiolino%2C+R.&rft.au=Marconi%2C+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-47"><a href="#cite_ref-47">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPeimbert1967" class="citation journal cs1">Peimbert, Manuel (December 1967). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F149385">"Temperature determinations of HII regions"</a>. <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 150: 825. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1967ApJ...150..825P">1967ApJ...150..825P</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F149385">10.1086/149385</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Temperature+determinations+of+H%3Csup%3EII%3C%2Fsup%3E+regions&rft.volume=150&rft.pages=825&rft.date=1967-12&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F149385&rft_id=info%3Abibcode%2F1967ApJ...150..825P&rft.aulast=Peimbert&rft.aufirst=Manuel&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F149385&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-48"><a href="#cite_ref-48">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPagel1986" class="citation journal cs1">Pagel, B.E.J. (1986). <a rel="nofollow" class="external text" href="http://stacks.iop.org/1538-3873/98/i=608/a=1009">"Nebulae and abundances in galaxies"</a>. <a href="/wiki/Publications_of_the_Astronomical_Society_of_the_Pacific" title="Publications of the Astronomical Society of the Pacific">Publications of the Astronomical Society of the Pacific</a>. 98 (608): 1009. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1986PASP...98.1009P">1986PASP...98.1009P</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F131863">10.1086/131863</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1538-3873">1538-3873</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:120467036">120467036</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Publications+of+the+Astronomical+Society+of+the+Pacific&rft.atitle=Nebulae+and+abundances+in+galaxies&rft.volume=98&rft.issue=608&rft.pages=1009&rft.date=1986&rft_id=info%3Adoi%2F10.1086%2F131863&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A120467036%23id-name%3DS2CID&rft.issn=1538-3873&rft_id=info%3Abibcode%2F1986PASP...98.1009P&rft.aulast=Pagel&rft.aufirst=B.E.J.&rft_id=http%3A%2F%2Fstacks.iop.org%2F1538-3873%2F98%2Fi%3D608%2Fa%3D1009&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-49"><a href="#cite_ref-49">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHenryWorthey1999" class="citation journal cs1">Henry, R.B.C.; Worthey, Guy (August 1999). "The distribution of heavy elements in spiral and elliptical galaxies". <a href="/wiki/Publications_of_the_Astronomical_Society_of_the_Pacific" title="Publications of the Astronomical Society of the Pacific">Publications of the Astronomical Society of the Pacific</a>. 111 (762): 919–945. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/9904017">astro-ph/9904017</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1999PASP..111..919H">1999PASP..111..919H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F316403">10.1086/316403</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-6280">0004-6280</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:17106463">17106463</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Publications+of+the+Astronomical+Society+of+the+Pacific&rft.atitle=The+distribution+of+heavy+elements+in+spiral+and+elliptical+galaxies&rft.volume=111&rft.issue=762&rft.pages=919-945&rft.date=1999-08&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A17106463%23id-name%3DS2CID&rft_id=info%3Abibcode%2F1999PASP..111..919H&rft_id=info%3Aarxiv%2Fastro-ph%2F9904017&rft.issn=0004-6280&rft_id=info%3Adoi%2F10.1086%2F316403&rft.aulast=Henry&rft.aufirst=R.B.C.&rft.au=Worthey%2C+Guy&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-50"><a href="#cite_ref-50">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKobulnickyKennicuttPizagno1999" class="citation journal cs1">Kobulnicky, Henry A.; Kennicutt, Robert C. Jr.; Pizagno, James L. (April 1999). "On measuring nebular chemical abundances in distant galaxies using global emission-line spectra". <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 514 (2): 544–557. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/9811006">astro-ph/9811006</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1999ApJ...514..544K">1999ApJ...514..544K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F306987">10.1086/306987</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:14643540">14643540</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=On+measuring+nebular+chemical+abundances+in+distant+galaxies+using+global+emission-line+spectra&rft.volume=514&rft.issue=2&rft.pages=544-557&rft.date=1999-04&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A14643540%23id-name%3DS2CID&rft_id=info%3Abibcode%2F1999ApJ...514..544K&rft_id=info%3Aarxiv%2Fastro-ph%2F9811006&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F306987&rft.aulast=Kobulnicky&rft.aufirst=Henry+A.&rft.au=Kennicutt%2C+Robert+C.+Jr.&rft.au=Pizagno%2C+James+L.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-Grazyna-2004-Esteban-etal-51">^ <a href="#cite_ref-Grazyna-2004-Esteban-etal_51-0">a</a> <a href="#cite_ref-Grazyna-2004-Esteban-etal_51-1">b</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFGrazyna2004" class="citation book cs1">Grazyna, Stasinska (2004). "Abundance determinations in HII regions and planetary nebulae". In Esteban, C.; Garcia Lopez, R.J.; Herrero, A.; Sanchez, F. (eds.). Cosmochemistry: The melting pot of the elements. Cambridge Contemporary Astrophysics. Cambridge University Press. pp. 115–170. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/0207500">astro-ph/0207500</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2002astro.ph..7500S">2002astro.ph..7500S</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Abundance+determinations+in+H%3Csup%3EII%3C%2Fsup%3E+regions+and+planetary+nebulae&rft.btitle=Cosmochemistry%3A+The+melting+pot+of+the+elements&rft.series=Cambridge+Contemporary+Astrophysics&rft.pages=115-170&rft.pub=Cambridge+University+Press&rft.date=2004&rft_id=info%3Aarxiv%2Fastro-ph%2F0207500&rft_id=info%3Abibcode%2F2002astro.ph..7500S&rft.aulast=Grazyna&rft.aufirst=Stasinska&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-52"><a href="#cite_ref-52">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPeimbertPeimbertRuiz2005" class="citation journal cs1">Peimbert, Antonio; Peimbert, Manuel; Ruiz, Maria Teresa (December 2005). "Chemical composition of two HII regions in NGC 6822 based on VLT spectroscopy". <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 634 (2): 1056–1066. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/0507084">astro-ph/0507084</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2005ApJ...634.1056P">2005ApJ...634.1056P</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F444557">10.1086/444557</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:17086551">17086551</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Chemical+composition+of+two+H%3Csup%3EII%3C%2Fsup%3E+regions+in+NGC+6822+based+on+VLT+spectroscopy&rft.volume=634&rft.issue=2&rft.pages=1056-1066&rft.date=2005-12&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A17086551%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2005ApJ...634.1056P&rft_id=info%3Aarxiv%2Fastro-ph%2F0507084&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F444557&rft.aulast=Peimbert&rft.aufirst=Antonio&rft.au=Peimbert%2C+Manuel&rft.au=Ruiz%2C+Maria+Teresa&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-53"><a href="#cite_ref-53">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPagelEdmundsBlackwellChun1979" class="citation journal cs1">Pagel, B.E.J.; Edmunds, M.G.; Blackwell, D.E.; Chun, M.S.; Smith, G. (1979-11-01). <a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fmnras%2F189.1.95">"On the composition of HII regions in southern galaxies – I. NGC 300 and 1365"</a>. <a href="/wiki/Monthly_Notices_of_the_Royal_Astronomical_Society" title="Monthly Notices of the Royal Astronomical Society">Monthly Notices of the Royal Astronomical Society</a>. 189 (1): 95–113. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1979MNRAS.189...95P">1979MNRAS.189...95P</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fmnras%2F189.1.95">10.1093/mnras/189.1.95</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0035-8711">0035-8711</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Monthly+Notices+of+the+Royal+Astronomical+Society&rft.atitle=On+the+composition+of+H%3Csup%3EII%3C%2Fsup%3E+regions+in+southern+galaxies+%E2%80%93+I.+NGC+300+and+1365&rft.volume=189&rft.issue=1&rft.pages=95-113&rft.date=1979-11-01&rft.issn=0035-8711&rft_id=info%3Adoi%2F10.1093%2Fmnras%2F189.1.95&rft_id=info%3Abibcode%2F1979MNRAS.189...95P&rft.aulast=Pagel&rft.aufirst=B.E.J.&rft.au=Edmunds%2C+M.G.&rft.au=Blackwell%2C+D.E.&rft.au=Chun%2C+M.S.&rft.au=Smith%2C+G.&rft_id=https%3A%2F%2Fdoi.org%2F10.1093%252Fmnras%252F189.1.95&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-54"><a href="#cite_ref-54">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDopitaEvans1986" class="citation journal cs1">Dopita, M.A.; Evans, I.N. (August 1986). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F164432">"Theoretical models for HII regions. II - The extragalactic HII region abundance sequence"</a>. The Astrophysical Journal. 307: 431. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1986ApJ...307..431D">1986ApJ...307..431D</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F164432">10.1086/164432</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Theoretical+models+for+H%3Csup%3EII%3C%2Fsup%3E+regions.+II+-+The+extragalactic+H%3Csup%3EII%3C%2Fsup%3E+region+abundance+sequence&rft.volume=307&rft.pages=431&rft.date=1986-08&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F164432&rft_id=info%3Abibcode%2F1986ApJ...307..431D&rft.aulast=Dopita&rft.aufirst=M.A.&rft.au=Evans%2C+I.N.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F164432&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-55"><a href="#cite_ref-55">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMcGaugh1991" class="citation journal cs1">McGaugh, Stacy S. (October 1991). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F170569">"HII region abundances - Model oxygen line ratios"</a>. <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 380: 140. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1991ApJ...380..140M">1991ApJ...380..140M</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F170569">10.1086/170569</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=H%3Csup%3EII%3C%2Fsup%3E+region+abundances+-+Model+oxygen+line+ratios&rft.volume=380&rft.pages=140&rft.date=1991-10&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F170569&rft_id=info%3Abibcode%2F1991ApJ...380..140M&rft.aulast=McGaugh&rft.aufirst=Stacy+S.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F170569&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-56"><a href="#cite_ref-56">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPilyugin2001" class="citation journal cs1">Pilyugin, L.S. (April 2001). <a rel="nofollow" class="external text" href="https://www.aanda.org/articles/aa/ps/2001/14/aa10396.ps.gz">"On the oxygen abundance determination in HII regions"</a>. <a href="/wiki/Astronomy_%26_Astrophysics" title="Astronomy & Astrophysics">Astronomy & Astrophysics</a>. 369 (2): 594–604. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/0101446">astro-ph/0101446</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2001A&A...369..594P">2001A&A...369..594P</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1051%2F0004-6361%3A20010079">10.1051/0004-6361:20010079</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-6361">0004-6361</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:54527173">54527173</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomy+%26+Astrophysics&rft.atitle=On+the+oxygen+abundance+determination+in+H%3Csup%3EII%3C%2Fsup%3E+regions&rft.volume=369&rft.issue=2&rft.pages=594-604&rft.date=2001-04&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A54527173%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2001A%26A...369..594P&rft_id=info%3Aarxiv%2Fastro-ph%2F0101446&rft.issn=0004-6361&rft_id=info%3Adoi%2F10.1051%2F0004-6361%3A20010079&rft.aulast=Pilyugin&rft.aufirst=L.S.&rft_id=https%3A%2F%2Fwww.aanda.org%2Farticles%2Faa%2Fps%2F2001%2F14%2Faa10396.ps.gz&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-57"><a href="#cite_ref-57">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKobulnickyZaritsky1999" class="citation journal cs1">Kobulnicky, Henry A.; Zaritsky, Dennis (1999-01-20). "Chemical Properties of Star-forming Emission-Line Galaxies atz=0.1–0.5". <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 511 (1): 118–135. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/9808081">astro-ph/9808081</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1999ApJ...511..118K">1999ApJ...511..118K</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F306673">10.1086/306673</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:13094276">13094276</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Chemical+Properties+of+Star-forming+Emission-Line+Galaxies+atz%3D0.1%E2%80%930.5&rft.volume=511&rft.issue=1&rft.pages=118-135&rft.date=1999-01-20&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A13094276%23id-name%3DS2CID&rft_id=info%3Abibcode%2F1999ApJ...511..118K&rft_id=info%3Aarxiv%2Fastro-ph%2F9808081&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F306673&rft.aulast=Kobulnicky&rft.aufirst=Henry+A.&rft.au=Zaritsky%2C+Dennis&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-58"><a href="#cite_ref-58">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDiazPerez-Montero2000" class="citation journal cs1">Diaz, A.I.; Perez-Montero, E. (2000-02-11). <a rel="nofollow" class="external text" href="https://doi.org/10.1046%2Fj.1365-8711.2000.03117.x">"An empirical calibration of nebular abundances based on the sulphur emission lines"</a>. <a href="/wiki/Monthly_Notices_of_the_Royal_Astronomical_Society" title="Monthly Notices of the Royal Astronomical Society">Monthly Notices of the Royal Astronomical Society</a>. 312 (1): 130–138. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/9909492">astro-ph/9909492</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2000MNRAS.312..130D">2000MNRAS.312..130D</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1046%2Fj.1365-8711.2000.03117.x">10.1046/j.1365-8711.2000.03117.x</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0035-8711">0035-8711</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:119504048">119504048</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Monthly+Notices+of+the+Royal+Astronomical+Society&rft.atitle=An+empirical+calibration+of+nebular+abundances+based+on+the+sulphur+emission+lines&rft.volume=312&rft.issue=1&rft.pages=130-138&rft.date=2000-02-11&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A119504048%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2000MNRAS.312..130D&rft_id=info%3Aarxiv%2Fastro-ph%2F9909492&rft.issn=0035-8711&rft_id=info%3Adoi%2F10.1046%2Fj.1365-8711.2000.03117.x&rft.aulast=Diaz&rft.aufirst=A.I.&rft.au=Perez-Montero%2C+E.&rft_id=https%3A%2F%2Fdoi.org%2F10.1046%252Fj.1365-8711.2000.03117.x&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-59"><a href="#cite_ref-59">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFShaverMcGeeNewtonDanks1983" class="citation journal cs1">Shaver, P.A.; McGee, R.X.; Newton, L.M.; Danks, A.C.; Pottasch, S.R. (1983-09-01). <a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fmnras%2F204.1.53">"The galactic abundance gradient"</a>. <a href="/wiki/Monthly_Notices_of_the_Royal_Astronomical_Society" title="Monthly Notices of the Royal Astronomical Society">Monthly Notices of the Royal Astronomical Society</a>. 204 (1): 53–112. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1983MNRAS.204...53S">1983MNRAS.204...53S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fmnras%2F204.1.53">10.1093/mnras/204.1.53</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0035-8711">0035-8711</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Monthly+Notices+of+the+Royal+Astronomical+Society&rft.atitle=The+galactic+abundance+gradient&rft.volume=204&rft.issue=1&rft.pages=53-112&rft.date=1983-09-01&rft.issn=0035-8711&rft_id=info%3Adoi%2F10.1093%2Fmnras%2F204.1.53&rft_id=info%3Abibcode%2F1983MNRAS.204...53S&rft.aulast=Shaver&rft.aufirst=P.A.&rft.au=McGee%2C+R.X.&rft.au=Newton%2C+L.M.&rft.au=Danks%2C+A.C.&rft.au=Pottasch%2C+S.R.&rft_id=https%3A%2F%2Fdoi.org%2F10.1093%252Fmnras%252F204.1.53&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-60"><a href="#cite_ref-60">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAfflerbachChurchwellWerner1997" class="citation journal cs1">Afflerbach, A.; Churchwell, E.; Werner, M. W. (1997-03-20). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F303771">"Galactic abundance gradients from infrared fine-structure lines in compact HII regions"</a>. <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 478 (1): 190–205. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1997ApJ...478..190A">1997ApJ...478..190A</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F303771">10.1086/303771</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=Galactic+abundance+gradients+from+infrared+fine-structure+lines+in+compact+H%3Csup%3EII%3C%2Fsup%3E+regions&rft.volume=478&rft.issue=1&rft.pages=190-205&rft.date=1997-03-20&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1086%2F303771&rft_id=info%3Abibcode%2F1997ApJ...478..190A&rft.aulast=Afflerbach&rft.aufirst=A.&rft.au=Churchwell%2C+E.&rft.au=Werner%2C+M.+W.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F303771&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-61"><a href="#cite_ref-61">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPagelBernard1997" class="citation book cs1">Pagel, J.; Bernard, E. (1997). Nucleosynthesis and Chemical Evolution of Galaxies. Cambridge University Press. p. 392. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1997nceg.book.....P">1997nceg.book.....P</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-521-55061-1" title="Special:BookSources/978-0-521-55061-1"><bdi>978-0-521-55061-1</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Nucleosynthesis+and+Chemical+Evolution+of+Galaxies&rft.pages=392&rft.pub=Cambridge+University+Press&rft.date=1997&rft_id=info%3Abibcode%2F1997nceg.book.....P&rft.isbn=978-0-521-55061-1&rft.aulast=Pagel&rft.aufirst=J.&rft.au=Bernard%2C+E.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> <li id="cite_note-62"><a href="#cite_ref-62">^</a> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBalserRoodBaniaAnderson2011" class="citation journal cs1">Balser, Dana S.; Rood, Robert T.; Bania, T.M.; Anderson, L.D. (2011-08-10). "HII region metallicity distribution in the Milky Way disk". <a href="/wiki/The_Astrophysical_Journal" title="The Astrophysical Journal">The Astrophysical Journal</a>. 738 (1): 27. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/1106.1660">1106.1660</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2011ApJ...738...27B">2011ApJ...738...27B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1088%2F0004-637X%2F738%2F1%2F27">10.1088/0004-637X/738/1/27</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0004-637X">0004-637X</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:119252119">119252119</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Astrophysical+Journal&rft.atitle=H%3Csup%3EII%3C%2Fsup%3E+region+metallicity+distribution+in+the+Milky+Way+disk&rft.volume=738&rft.issue=1&rft.pages=27&rft.date=2011-08-10&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A119252119%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2011ApJ...738...27B&rft_id=info%3Aarxiv%2F1106.1660&rft.issn=0004-637X&rft_id=info%3Adoi%2F10.1088%2F0004-637X%2F738%2F1%2F27&rft.aulast=Balser&rft.aufirst=Dana+S.&rft.au=Rood%2C+Robert+T.&rft.au=Bania%2C+T.M.&rft.au=Anderson%2C+L.D.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"> </li> </ol></div> <style data-mw-deduplicate="TemplateStyles:r1239549316">.mw-parser-output .refbegin{margin-bottom:0.5em}.mw-parser-output .refbegin-hanging-indents>ul{margin-left:0}.mw-parser-output .refbegin-hanging-indents>ul>li{margin-left:0;padding-left:3.2em;text-indent:-3.2em}.mw-parser-output .refbegin-hanging-indents ul,.mw-parser-output .refbegin-hanging-indents ul li{list-style:none}@media(max-width:720px){.mw-parser-output .refbegin-hanging-indents>ul>li{padding-left:1.6em;text-indent:-1.6em}}.mw-parser-output .refbegin-columns{margin-top:0.3em}.mw-parser-output .refbegin-columns ul{margin-top:0}.mw-parser-output .refbegin-columns li{page-break-inside:avoid;break-inside:avoid-column}@media screen{.mw-parser-output .refbegin{font-size:90%}}</style><div class="refbegin refbegin-columns references-column-width" style="column-width: 25em"> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSalvaterra,_R.Ferrara,_A.Schneider,_R.2004" class="citation journal cs1">Salvaterra, R.; Ferrara, A.; <a href="/wiki/Raffaella_Schneider" title="Raffaella Schneider">Schneider, R.</a> (2004). "Induced formation of primordial low-mass stars". <a href="/wiki/New_Astronomy_(journal)" title="New Astronomy (journal)">New Astronomy</a>. 10 (2): 113–120. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/0304074">astro-ph/0304074</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2004NewA...10..113S">2004NewA...10..113S</a>. <a href="/wiki/CiteSeerX_(identifier)" class="mw-redirect" title="CiteSeerX (identifier)">CiteSeerX</a> <a rel="nofollow" class="external text" href="https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.258.923">10.1.1.258.923</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.newast.2004.06.003">10.1016/j.newast.2004.06.003</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:15085880">15085880</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=New+Astronomy&rft.atitle=Induced+formation+of+primordial+low-mass+stars&rft.volume=10&rft.issue=2&rft.pages=113-120&rft.date=2004&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A15085880%23id-name%3DS2CID&rft_id=info%3Abibcode%2F2004NewA...10..113S&rft_id=https%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fsummary%3Fdoi%3D10.1.1.258.923%23id-name%3DCiteSeerX&rft_id=info%3Adoi%2F10.1016%2Fj.newast.2004.06.003&rft_id=info%3Aarxiv%2Fastro-ph%2F0304074&rft.au=Salvaterra%2C+R.&rft.au=Ferrara%2C+A.&rft.au=Schneider%2C+R.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHeger,_A.Woosley,_S.E.2002" class="citation journal cs1">Heger, A.; Woosley, S.E. (2002). "The nucleosynthetic signature of population III". <a href="/wiki/Astrophysical_Journal" class="mw-redirect" title="Astrophysical Journal">Astrophysical Journal</a>. 567 (1): 532–543. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/0107037">astro-ph/0107037</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2002ApJ...567..532H">2002ApJ...567..532H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F338487">10.1086/338487</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:16050642">16050642</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astrophysical+Journal&rft.atitle=The+nucleosynthetic+signature+of+population+III&rft.volume=567&rft.issue=1&rft.pages=532-543&rft.date=2002&rft_id=info%3Aarxiv%2Fastro-ph%2F0107037&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A16050642%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1086%2F338487&rft_id=info%3Abibcode%2F2002ApJ...567..532H&rft.au=Heger%2C+A.&rft.au=Woosley%2C+S.E.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"></li></ul> </div> </section><div class="mw-heading mw-heading2 section-heading" onclick="mfTempOpenSection(8)"><h2 id="Further_reading">Further reading</h2> <a role="button" href="/w/index.php?title=Metallicity&action=edit&section=14" title="Edit section: Further reading" class="cdx-button cdx-button--size-large cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--icon-only cdx-button--weight-quiet "> edit </a> </div><section class="mf-section-8 collapsible-block" id="mf-section-8"> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKuhnKoupelis2004" class="citation book cs1">Kuhn, Karl F.; Koupelis, Theo (2004). Quest of the Universe (Fourth ed.). Canada: Jones and Bartlett. p. 593. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-7637-0810-0" title="Special:BookSources/0-7637-0810-0"><bdi>0-7637-0810-0</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Quest+of+the+Universe&rft.place=Canada&rft.pages=593&rft.edition=Fourth&rft.pub=Jones+and+Bartlett&rft.date=2004&rft.isbn=0-7637-0810-0&rft.aulast=Kuhn&rft.aufirst=Karl+F.&rft.au=Koupelis%2C+Theo&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBrommLarson2004" class="citation journal cs1">Bromm, Volker; Larson, Richard B. (2004). "The first stars". <a href="/wiki/Annual_Review_of_Astronomy_and_Astrophysics" title="Annual Review of Astronomy and Astrophysics">Annual Review of Astronomy and Astrophysics</a>. 42 (1): 79–118. <a href="/wiki/ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<a rel="nofollow" class="external text" href="https://arxiv.org/abs/astro-ph/0311019">astro-ph/0311019</a>. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2004ARA&A..42...79B">2004ARA&A..42...79B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1146%2Fannurev.astro.42.053102.134034">10.1146/annurev.astro.42.053102.134034</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:119371063">119371063</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Annual+Review+of+Astronomy+and+Astrophysics&rft.atitle=The+first+stars&rft.volume=42&rft.issue=1&rft.pages=79-118&rft.date=2004&rft_id=info%3Aarxiv%2Fastro-ph%2F0311019&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A119371063%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1146%2Fannurev.astro.42.053102.134034&rft_id=info%3Abibcode%2F2004ARA%26A..42...79B&rft.aulast=Bromm&rft.aufirst=Volker&rft.au=Larson%2C+Richard+B.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMetallicity" class="Z3988"></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist 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href="/w/index.php?title=Metallicity&action=history"> <div class="post-content last-modified-bar__content"> Last edited on 7 November 2024, at 21:26 </div> </a> <div class="post-content footer-content"> <div id='mw-data-after-content'> <div class="read-more-container"></div> </div> <div id="p-lang"> <h4>Languages</h4> <section> <ul id="p-variants" class="minerva-languages"></ul> <ul class="minerva-languages"><li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/Metaal_(sterrekunde)" title="Metaal (sterrekunde) – Afrikaans" lang="af" hreflang="af" data-title="Metaal (sterrekunde)" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target">Afrikaans</a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%85%D8%B9%D8%AF%D9%86%D9%8A%D8%A9_(%D8%B9%D9%84%D9%85_%D8%A7%D9%84%D9%81%D9%84%D9%83)" title="معدنية (علم الفلك) – Arabic" lang="ar" hreflang="ar" data-title="معدنية (علم الفلك)" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target">العربية</a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/Metalicid%C3%A1" title="Metalicidá – Asturian" lang="ast" hreflang="ast" data-title="Metalicidá" data-language-autonym="Asturianu" data-language-local-name="Asturian" class="interlanguage-link-target">Asturianu</a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%A7%E0%A6%BE%E0%A6%A4%E0%A6%AC%E0%A6%A4%E0%A6%BE" title="ধাতবতা – Bangla" lang="bn" hreflang="bn" data-title="ধাতবতা" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target">বাংলা</a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9C%D0%B5%D1%82%D0%B0%D0%BB%D0%B8%D1%87%D0%BD%D0%BE%D1%81%D1%82" title="Металичност – Bulgarian" lang="bg" hreflang="bg" data-title="Металичност" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target">Български</a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Metalicitet" title="Metalicitet – Bosnian" lang="bs" hreflang="bs" data-title="Metalicitet" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target">Bosanski</a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Metal%C2%B7licitat" title="Metal·licitat – Catalan" lang="ca" hreflang="ca" data-title="Metal·licitat" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target">Català</a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Metalicita" title="Metalicita – Czech" lang="cs" hreflang="cs" data-title="Metalicita" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target">Čeština</a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Metallicitet_(astrofysik)" title="Metallicitet (astrofysik) – Danish" lang="da" hreflang="da" data-title="Metallicitet (astrofysik)" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target">Dansk</a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Metallizit%C3%A4t" title="Metallizität – German" lang="de" hreflang="de" data-title="Metallizität" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target">Deutsch</a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%9C%CE%B5%CF%84%CE%B1%CE%BB%CE%BB%CE%B9%CE%BA%CF%8C%CF%84%CE%B7%CF%84%CE%B1" title="Μεταλλικότητα – Greek" lang="el" hreflang="el" data-title="Μεταλλικότητα" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target">Ελληνικά</a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Metalicidad" title="Metalicidad – Spanish" lang="es" hreflang="es" data-title="Metalicidad" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target">Español</a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Kvanto_de_pezaj_elementoj" title="Kvanto de pezaj elementoj – Esperanto" lang="eo" hreflang="eo" data-title="Kvanto de pezaj elementoj" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target">Esperanto</a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Metaltasun" title="Metaltasun – Basque" lang="eu" hreflang="eu" data-title="Metaltasun" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target">Euskara</a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%81%D9%84%D8%B2%DB%8C%D9%86%DA%AF%DB%8C" title="فلزینگی – Persian" lang="fa" hreflang="fa" data-title="فلزینگی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target">فارسی</a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/M%C3%A9tallicit%C3%A9" title="Métallicité – French" lang="fr" hreflang="fr" data-title="Métallicité" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target">Français</a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Metalicidade" title="Metalicidade – Galician" lang="gl" hreflang="gl" data-title="Metalicidade" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target">Galego</a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EA%B8%88%EC%86%8D%ED%95%A8%EB%9F%89" title="금속함량 – Korean" lang="ko" hreflang="ko" data-title="금속함량" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target">한국어</a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%A7%E0%A4%BE%E0%A4%A4%E0%A5%81%E0%A4%A4%E0%A4%BE" title="धातुता – Hindi" lang="hi" hreflang="hi" data-title="धातुता" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target">हिन्दी</a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Populacija_I" title="Populacija I – Croatian" lang="hr" hreflang="hr" data-title="Populacija I" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target">Hrvatski</a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Metalisitas" title="Metalisitas – Indonesian" lang="id" hreflang="id" data-title="Metalisitas" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target">Bahasa Indonesia</a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Metallicit%C3%A0" title="Metallicità – Italian" lang="it" hreflang="it" data-title="Metallicità" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target">Italiano</a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%9E%D7%AA%D7%9B%D7%AA%D7%99%D7%95%D7%AA" title="מתכתיות – Hebrew" lang="he" hreflang="he" data-title="מתכתיות" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target">עברית</a></li><li class="interlanguage-link interwiki-lb mw-list-item"><a href="https://lb.wikipedia.org/wiki/Metallizit%C3%A9it" title="Metallizitéit – Luxembourgish" lang="lb" hreflang="lb" data-title="Metallizitéit" data-language-autonym="Lëtzebuergesch" data-language-local-name="Luxembourgish" class="interlanguage-link-target">Lëtzebuergesch</a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%9C%D0%B5%D1%82%D0%B0%D0%BB%D0%B8%D1%87%D0%BD%D0%BE%D1%81%D1%82" title="Металичност – Macedonian" lang="mk" hreflang="mk" data-title="Металичност" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target">Македонски</a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Kelogaman" title="Kelogaman – Malay" lang="ms" hreflang="ms" data-title="Kelogaman" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target">Bahasa Melayu</a></li><li class="interlanguage-link interwiki-my mw-list-item"><a href="https://my.wikipedia.org/wiki/%E1%80%9E%E1%80%90%E1%80%B9%E1%80%90%E1%80%AF%E1%80%80%E1%80%BC%E1%80%BD%E1%80%9A%E1%80%BA%E1%80%9D%E1%80%99%E1%80%BE%E1%80%AF" title="သတ္တုကြွယ်ဝမှု – Burmese" lang="my" hreflang="my" data-title="သတ္တုကြွယ်ဝမှု" data-language-autonym="မြန်မာဘာသာ" data-language-local-name="Burmese" class="interlanguage-link-target">မြန်မာဘာသာ</a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Metaal_(astronomie)" title="Metaal (astronomie) – Dutch" lang="nl" hreflang="nl" data-title="Metaal (astronomie)" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target">Nederlands</a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E9%87%91%E5%B1%9E%E9%87%8F" title="金属量 – Japanese" lang="ja" hreflang="ja" data-title="金属量" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target">日本語</a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Metallisitet" title="Metallisitet – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Metallisitet" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target">Norsk bokmål</a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Metallisitet" title="Metallisitet – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Metallisitet" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target">Norsk nynorsk</a></li><li class="interlanguage-link interwiki-oc mw-list-item"><a href="https://oc.wikipedia.org/wiki/Metallicitat" title="Metallicitat – Occitan" lang="oc" hreflang="oc" data-title="Metallicitat" data-language-autonym="Occitan" data-language-local-name="Occitan" class="interlanguage-link-target">Occitan</a></li><li class="interlanguage-link interwiki-nds mw-list-item"><a href="https://nds.wikipedia.org/wiki/Metallizit%C3%A4t" title="Metallizität – Low German" lang="nds" hreflang="nds" data-title="Metallizität" data-language-autonym="Plattdüütsch" data-language-local-name="Low German" class="interlanguage-link-target">Plattdüütsch</a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Metaliczno%C5%9B%C4%87" title="Metaliczność – Polish" lang="pl" hreflang="pl" data-title="Metaliczność" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target">Polski</a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Metalicidade" title="Metalicidade – Portuguese" lang="pt" hreflang="pt" data-title="Metalicidade" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target">Português</a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Metalicitate" title="Metalicitate – Romanian" lang="ro" hreflang="ro" data-title="Metalicitate" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target">Română</a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9C%D0%B5%D1%82%D0%B0%D0%BB%D0%BB%D0%B8%D1%87%D0%BD%D0%BE%D1%81%D1%82%D1%8C" title="Металличность – Russian" lang="ru" hreflang="ru" data-title="Металличность" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target">Русский</a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Metallicity" title="Metallicity – Simple English" lang="en-simple" hreflang="en-simple" data-title="Metallicity" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target">Simple English</a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Metalicita" title="Metalicita – Slovak" lang="sk" hreflang="sk" data-title="Metalicita" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target">Slovenčina</a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Kovinskost" title="Kovinskost – Slovenian" lang="sl" hreflang="sl" data-title="Kovinskost" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target">Slovenščina</a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/Metali%C4%8Dnost" title="Metaličnost – Serbian" lang="sr" hreflang="sr" data-title="Metaličnost" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target">Српски / srpski</a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Populacija_I" title="Populacija I – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Populacija I" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target">Srpskohrvatski / српскохрватски</a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/T%C3%A4hden_metallipitoisuus" title="Tähden metallipitoisuus – Finnish" lang="fi" hreflang="fi" data-title="Tähden metallipitoisuus" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target">Suomi</a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Metallicitet" title="Metallicitet – Swedish" lang="sv" hreflang="sv" data-title="Metallicitet" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target">Svenska</a></li><li class="interlanguage-link interwiki-kab mw-list-item"><a href="https://kab.wikipedia.org/wiki/Tama%C9%A3uzt" title="Tamaɣuzt – Kabyle" lang="kab" hreflang="kab" data-title="Tamaɣuzt" data-language-autonym="Taqbaylit" data-language-local-name="Kabyle" class="interlanguage-link-target">Taqbaylit</a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%84%E0%B8%A7%E0%B8%B2%E0%B8%A1%E0%B9%80%E0%B8%9B%E0%B9%87%E0%B8%99%E0%B9%82%E0%B8%A5%E0%B8%AB%E0%B8%B0_(%E0%B8%94%E0%B8%B2%E0%B8%A3%E0%B8%B2%E0%B8%A8%E0%B8%B2%E0%B8%AA%E0%B8%95%E0%B8%A3%E0%B9%8C)" title="ความเป็นโลหะ (ดาราศาสตร์) – Thai" lang="th" hreflang="th" data-title="ความเป็นโลหะ (ดาราศาสตร์)" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target">ไทย</a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Metallik" title="Metallik – Turkish" lang="tr" hreflang="tr" data-title="Metallik" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target">Türkçe</a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9C%D0%B5%D1%82%D0%B0%D0%BB%D1%96%D1%87%D0%BD%D1%96%D1%81%D1%82%D1%8C" title="Металічність – Ukrainian" lang="uk" hreflang="uk" data-title="Металічність" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target">Українська</a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/%C4%90%E1%BB%99_kim_lo%E1%BA%A1i" title="Độ kim loại – Vietnamese" lang="vi" hreflang="vi" data-title="Độ kim loại" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target">Tiếng Việt</a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%E9%87%91%E5%B1%AC%E9%87%8F" title="金屬量 – Cantonese" lang="yue" hreflang="yue" data-title="金屬量" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target">粵語</a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E9%87%91%E5%B1%AC%E9%87%8F" title="金屬量 – Chinese" lang="zh" hreflang="zh" data-title="金屬量" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target">中文</a></li></ul> </section> </div> <div class="minerva-footer-logo"><img src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" alt="Wikipedia" width="120" height="18" style="width: 7.5em; height: 1.125em;"/> </div> <ul id="footer-info" class="footer-info hlist hlist-separated"> <li id="footer-info-lastmod"> This page was last edited on 7 November 2024, at 21:26 (UTC).</li> <li 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