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class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Formation</span> </div> </a> <ul id="toc-Formation-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Types" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Types"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Types</span> </div> </a> <button aria-controls="toc-Types-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Types subsection</span> </button> <ul id="toc-Types-sublist" class="vector-toc-list"> <li id="toc-Classical_types" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Classical_types"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Classical types</span> </div> </a> <ul id="toc-Classical_types-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Flux_Nebulae" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Flux_Nebulae"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Flux Nebulae</span> </div> </a> <ul id="toc-Flux_Nebulae-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Diffuse_nebulae" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Diffuse_nebulae"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.3</span> <span>Diffuse nebulae</span> </div> </a> <ul id="toc-Diffuse_nebulae-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Planetary_nebulae" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Planetary_nebulae"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4</span> <span>Planetary nebulae</span> </div> </a> <ul id="toc-Planetary_nebulae-sublist" class="vector-toc-list"> <li id="toc-Protoplanetary_nebulae" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Protoplanetary_nebulae"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.4.1</span> <span>Protoplanetary nebulae</span> </div> </a> <ul id="toc-Protoplanetary_nebulae-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Supernova_remnants" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Supernova_remnants"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.5</span> <span>Supernova remnants</span> </div> </a> <ul id="toc-Supernova_remnants-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Examples" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Examples"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Examples</span> </div> </a> <button aria-controls="toc-Examples-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Examples subsection</span> </button> <ul id="toc-Examples-sublist" class="vector-toc-list"> <li id="toc-Catalogs" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Catalogs"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.1</span> <span>Catalogs</span> </div> </a> <ul id="toc-Catalogs-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" title="Table of Contents" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Nebula</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 109 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-109" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">109 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/Newel" title="Newel – Afrikaans" lang="af" hreflang="af" data-title="Newel" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-anp mw-list-item"><a href="https://anp.wikipedia.org/wiki/%E0%A4%A8%E0%A4%BF%E0%A4%B9%E0%A4%BE%E0%A4%B0%E0%A4%BF%E0%A4%95%E0%A4%BE" title="निहारिका – Angika" lang="anp" hreflang="anp" data-title="निहारिका" data-language-autonym="अंगिका" data-language-local-name="Angika" class="interlanguage-link-target"><span>अंगिका</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%B3%D8%AF%D9%8A%D9%85" title="سديم – Arabic" lang="ar" hreflang="ar" data-title="سديم" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-an mw-list-item"><a href="https://an.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Aragonese" lang="an" hreflang="an" data-title="Nebulosa" data-language-autonym="Aragonés" data-language-local-name="Aragonese" class="interlanguage-link-target"><span>Aragonés</span></a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Asturian" lang="ast" hreflang="ast" data-title="Nebulosa" data-language-autonym="Asturianu" data-language-local-name="Asturian" class="interlanguage-link-target"><span>Asturianu</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/Dumanl%C4%B1q" title="Dumanlıq – Azerbaijani" lang="az" hreflang="az" data-title="Dumanlıq" data-language-autonym="Azərbaycanca" data-language-local-name="Azerbaijani" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%A8%E0%A7%80%E0%A6%B9%E0%A6%BE%E0%A6%B0%E0%A6%BF%E0%A6%95%E0%A6%BE" title="নীহারিকা – Bangla" lang="bn" hreflang="bn" data-title="নীহারিকা" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-bjn mw-list-item"><a href="https://bjn.wikipedia.org/wiki/Nebula" title="Nebula – Banjar" lang="bjn" hreflang="bjn" data-title="Nebula" data-language-autonym="Banjar" data-language-local-name="Banjar" class="interlanguage-link-target"><span>Banjar</span></a></li><li class="interlanguage-link interwiki-zh-min-nan mw-list-item"><a href="https://zh-min-nan.wikipedia.org/wiki/Chhi%E2%81%BF-h%C3%BBn" title="Chhiⁿ-hûn – Minnan" lang="nan" hreflang="nan" data-title="Chhiⁿ-hûn" data-language-autonym="閩南語 / Bân-lâm-gú" data-language-local-name="Minnan" class="interlanguage-link-target"><span>閩南語 / Bân-lâm-gú</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%A2%D1%83%D0%BC%D0%B0%D0%BD%D0%BD%D0%B0%D1%81%D1%86%D1%8C" title="Туманнасць – Belarusian" lang="be" hreflang="be" data-title="Туманнасць" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-be-x-old mw-list-item"><a href="https://be-tarask.wikipedia.org/wiki/%D0%A2%D1%83%D0%BC%D0%B0%D0%BD%D0%BD%D0%B0%D1%81%D1%8C%D1%86%D1%8C" title="Туманнасьць – Belarusian (Taraškievica orthography)" lang="be-tarask" hreflang="be-tarask" data-title="Туманнасьць" data-language-autonym="Беларуская (тарашкевіца)" data-language-local-name="Belarusian (Taraškievica orthography)" class="interlanguage-link-target"><span>Беларуская (тарашкевіца)</span></a></li><li class="interlanguage-link interwiki-bh mw-list-item"><a href="https://bh.wikipedia.org/wiki/%E0%A4%A8%E0%A5%87%E0%A4%AC%E0%A5%81%E0%A4%B2%E0%A4%BE" title="नेबुला – Bhojpuri" lang="bh" hreflang="bh" data-title="नेबुला" data-language-autonym="भोजपुरी" data-language-local-name="Bhojpuri" class="interlanguage-link-target"><span>भोजपुरी</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9C%D1%8A%D0%B3%D0%BB%D1%8F%D0%B2%D0%B8%D0%BD%D0%B0" title="Мъглявина – Bulgarian" lang="bg" hreflang="bg" data-title="Мъглявина" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Maglina" title="Maglina – Bosnian" lang="bs" hreflang="bs" data-title="Maglina" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-br mw-list-item"><a href="https://br.wikipedia.org/wiki/Nivlennad" title="Nivlennad – Breton" lang="br" hreflang="br" data-title="Nivlennad" data-language-autonym="Brezhoneg" data-language-local-name="Breton" class="interlanguage-link-target"><span>Brezhoneg</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Catalan" lang="ca" hreflang="ca" data-title="Nebulosa" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cv mw-list-item"><a href="https://cv.wikipedia.org/wiki/%D0%A2%C4%95%D1%82%D1%80%D0%B5%D0%BB%C4%95%D1%85_(%D0%B0%D1%81%D1%82%D1%80%D0%BE%D1%84%D0%B8%D0%B7%D0%B8%D0%BA%D0%B0)" title="Тĕтрелĕх (астрофизика) – Chuvash" lang="cv" hreflang="cv" data-title="Тĕтрелĕх (астрофизика)" data-language-autonym="Чӑвашла" data-language-local-name="Chuvash" class="interlanguage-link-target"><span>Чӑвашла</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Mlhovina" title="Mlhovina – Czech" lang="cs" hreflang="cs" data-title="Mlhovina" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-co mw-list-item"><a href="https://co.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Corsican" lang="co" hreflang="co" data-title="Nebulosa" data-language-autonym="Corsu" data-language-local-name="Corsican" class="interlanguage-link-target"><span>Corsu</span></a></li><li class="interlanguage-link interwiki-cy mw-list-item"><a href="https://cy.wikipedia.org/wiki/Nifwl" title="Nifwl – Welsh" lang="cy" hreflang="cy" data-title="Nifwl" data-language-autonym="Cymraeg" data-language-local-name="Welsh" class="interlanguage-link-target"><span>Cymraeg</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Stjernet%C3%A5ge" title="Stjernetåge – Danish" lang="da" hreflang="da" data-title="Stjernetåge" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Nebel_(Astronomie)" title="Nebel (Astronomie) – German" lang="de" hreflang="de" data-title="Nebel (Astronomie)" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Udukogu" title="Udukogu – Estonian" lang="et" hreflang="et" data-title="Udukogu" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%9D%CE%B5%CF%86%CE%AD%CE%BB%CF%89%CE%BC%CE%B1" title="Νεφέλωμα – Greek" lang="el" hreflang="el" data-title="Νεφέλωμα" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Spanish" lang="es" hreflang="es" data-title="Nebulosa" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Nebulozo" title="Nebulozo – Esperanto" lang="eo" hreflang="eo" data-title="Nebulozo" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Basque" lang="eu" hreflang="eu" data-title="Nebulosa" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%B3%D8%AD%D8%A7%D8%A8%DB%8C" title="سحابی – Persian" lang="fa" hreflang="fa" data-title="سحابی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/N%C3%A9buleuse" title="Nébuleuse – French" lang="fr" hreflang="fr" data-title="Nébuleuse" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/R%C3%A9altn%C3%A9al" title="Réaltnéal – Irish" lang="ga" hreflang="ga" data-title="Réaltnéal" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gd mw-list-item"><a href="https://gd.wikipedia.org/wiki/Neul_(reul-e%C3%B2las)" title="Neul (reul-eòlas) – Scottish Gaelic" lang="gd" hreflang="gd" data-title="Neul (reul-eòlas)" data-language-autonym="Gàidhlig" data-language-local-name="Scottish Gaelic" class="interlanguage-link-target"><span>Gàidhlig</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Galician" lang="gl" hreflang="gl" data-title="Nebulosa" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-gu mw-list-item"><a href="https://gu.wikipedia.org/wiki/%E0%AA%A8%E0%AA%BF%E0%AA%B9%E0%AA%BE%E0%AA%B0%E0%AA%BF%E0%AA%95%E0%AA%BE" title="નિહારિકા – Gujarati" lang="gu" hreflang="gu" data-title="નિહારિકા" data-language-autonym="ગુજરાતી" data-language-local-name="Gujarati" class="interlanguage-link-target"><span>ગુજરાતી</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%84%B1%EC%9A%B4" title="성운 – Korean" lang="ko" hreflang="ko" data-title="성운" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D5%84%D5%AB%D5%A3%D5%A1%D5%B4%D5%A1%D5%AE%D5%B8%D6%82%D5%A9%D5%B5%D5%B8%D6%82%D5%B6" title="Միգամածություն – Armenian" lang="hy" hreflang="hy" data-title="Միգամածություն" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%A8%E0%A5%80%E0%A4%B9%E0%A4%BE%E0%A4%B0%E0%A4%BF%E0%A4%95%E0%A4%BE" title="नीहारिका – Hindi" lang="hi" hreflang="hi" data-title="नीहारिका" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Maglica" title="Maglica – Croatian" lang="hr" hreflang="hr" data-title="Maglica" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-io mw-list-item"><a href="https://io.wikipedia.org/wiki/Nebuloso" title="Nebuloso – Ido" lang="io" hreflang="io" data-title="Nebuloso" data-language-autonym="Ido" data-language-local-name="Ido" class="interlanguage-link-target"><span>Ido</span></a></li><li class="interlanguage-link interwiki-ig mw-list-item"><a href="https://ig.wikipedia.org/wiki/Nebula" title="Nebula – Igbo" lang="ig" hreflang="ig" data-title="Nebula" data-language-autonym="Igbo" data-language-local-name="Igbo" class="interlanguage-link-target"><span>Igbo</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Nebula" title="Nebula – Indonesian" lang="id" hreflang="id" data-title="Nebula" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-zu mw-list-item"><a href="https://zu.wikipedia.org/wiki/UmQongo" title="UmQongo – Zulu" lang="zu" hreflang="zu" data-title="UmQongo" data-language-autonym="IsiZulu" data-language-local-name="Zulu" class="interlanguage-link-target"><span>IsiZulu</span></a></li><li class="interlanguage-link interwiki-is mw-list-item"><a href="https://is.wikipedia.org/wiki/Gas%C3%BEoka" title="Gasþoka – Icelandic" lang="is" hreflang="is" data-title="Gasþoka" data-language-autonym="Íslenska" data-language-local-name="Icelandic" class="interlanguage-link-target"><span>Íslenska</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Italian" lang="it" hreflang="it" data-title="Nebulosa" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%A2%D7%A8%D7%A4%D7%99%D7%9C%D7%99%D7%AA" title="ערפילית – Hebrew" lang="he" hreflang="he" data-title="ערפילית" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-jv mw-list-item"><a href="https://jv.wikipedia.org/wiki/N%C3%A9bula" title="Nébula – Javanese" lang="jv" hreflang="jv" data-title="Nébula" data-language-autonym="Jawa" data-language-local-name="Javanese" class="interlanguage-link-target"><span>Jawa</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/%E1%83%9C%E1%83%98%E1%83%A1%E1%83%9A%E1%83%94%E1%83%A3%E1%83%9A%E1%83%94%E1%83%91%E1%83%98" title="ნისლეულები – Georgian" lang="ka" hreflang="ka" data-title="ნისლეულები" data-language-autonym="ქართული" data-language-local-name="Georgian" class="interlanguage-link-target"><span>ქართული</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%A2%D2%B1%D0%BC%D0%B0%D0%BD%D0%B4%D1%8B%D2%9B" title="Тұмандық – Kazakh" lang="kk" hreflang="kk" data-title="Тұмандық" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-sw mw-list-item"><a href="https://sw.wikipedia.org/wiki/Nebula" title="Nebula – Swahili" lang="sw" hreflang="sw" data-title="Nebula" data-language-autonym="Kiswahili" data-language-local-name="Swahili" class="interlanguage-link-target"><span>Kiswahili</span></a></li><li class="interlanguage-link interwiki-ht mw-list-item"><a href="https://ht.wikipedia.org/wiki/Nebilez" title="Nebilez – Haitian Creole" lang="ht" hreflang="ht" data-title="Nebilez" data-language-autonym="Kreyòl ayisyen" data-language-local-name="Haitian Creole" class="interlanguage-link-target"><span>Kreyòl ayisyen</span></a></li><li class="interlanguage-link interwiki-ku mw-list-item"><a href="https://ku.wikipedia.org/wiki/Nebuloz" title="Nebuloz – Kurdish" lang="ku" hreflang="ku" data-title="Nebuloz" data-language-autonym="Kurdî" data-language-local-name="Kurdish" class="interlanguage-link-target"><span>Kurdî</span></a></li><li class="interlanguage-link interwiki-lld mw-list-item"><a href="https://lld.wikipedia.org/wiki/Nebuleusa" title="Nebuleusa – Ladin" lang="lld" hreflang="lld" data-title="Nebuleusa" data-language-autonym="Ladin" data-language-local-name="Ladin" class="interlanguage-link-target"><span>Ladin</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Nebula_(astronomia)" title="Nebula (astronomia) – Latin" lang="la" hreflang="la" data-title="Nebula (astronomia)" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Migl%C4%81js" title="Miglājs – Latvian" lang="lv" hreflang="lv" data-title="Miglājs" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-lb mw-list-item"><a href="https://lb.wikipedia.org/wiki/Niwwel_(Astronomie)" title="Niwwel (Astronomie) – Luxembourgish" lang="lb" hreflang="lb" data-title="Niwwel (Astronomie)" data-language-autonym="Lëtzebuergesch" data-language-local-name="Luxembourgish" class="interlanguage-link-target"><span>Lëtzebuergesch</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/%C5%AAkas" title="Ūkas – Lithuanian" lang="lt" hreflang="lt" data-title="Ūkas" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-lfn mw-list-item"><a href="https://lfn.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Lingua Franca Nova" lang="lfn" hreflang="lfn" data-title="Nebulosa" data-language-autonym="Lingua Franca Nova" data-language-local-name="Lingua Franca Nova" class="interlanguage-link-target"><span>Lingua Franca Nova</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Csillagk%C3%B6d" title="Csillagköd – Hungarian" lang="hu" hreflang="hu" data-title="Csillagköd" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%9C%D0%B0%D0%B3%D0%BB%D0%B8%D0%BD%D0%B0" title="Маглина – Macedonian" lang="mk" hreflang="mk" data-title="Маглина" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%A8%E0%B5%86%E0%B4%AC%E0%B5%81%E0%B4%B2" title="നെബുല – Malayalam" lang="ml" hreflang="ml" data-title="നെബുല" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-mr mw-list-item"><a href="https://mr.wikipedia.org/wiki/%E0%A4%A4%E0%A5%87%E0%A4%9C%E0%A5%8B%E0%A4%AE%E0%A5%87%E0%A4%98" title="तेजोमेघ – Marathi" lang="mr" hreflang="mr" data-title="तेजोमेघ" data-language-autonym="मराठी" data-language-local-name="Marathi" class="interlanguage-link-target"><span>मराठी</span></a></li><li class="interlanguage-link interwiki-xmf mw-list-item"><a href="https://xmf.wikipedia.org/wiki/%E1%83%9C%E1%83%98%E1%83%A0%E1%83%A1%E1%83%94%E1%83%A3%E1%83%9A%E1%83%98" title="ნირსეული – Mingrelian" lang="xmf" hreflang="xmf" data-title="ნირსეული" data-language-autonym="მარგალური" data-language-local-name="Mingrelian" class="interlanguage-link-target"><span>მარგალური</span></a></li><li class="interlanguage-link interwiki-arz mw-list-item"><a href="https://arz.wikipedia.org/wiki/%D9%86%D9%8A%D8%A8%D9%88%D9%84%D8%A7" title="نيبولا – Egyptian Arabic" lang="arz" hreflang="arz" data-title="نيبولا" data-language-autonym="مصرى" data-language-local-name="Egyptian Arabic" class="interlanguage-link-target"><span>مصرى</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Nebula" title="Nebula – Malay" lang="ms" hreflang="ms" data-title="Nebula" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-min mw-list-item"><a href="https://min.wikipedia.org/wiki/Nebula" title="Nebula – Minangkabau" lang="min" hreflang="min" data-title="Nebula" data-language-autonym="Minangkabau" data-language-local-name="Minangkabau" class="interlanguage-link-target"><span>Minangkabau</span></a></li><li class="interlanguage-link interwiki-my mw-list-item"><a href="https://my.wikipedia.org/wiki/%E1%80%94%E1%80%80%E1%80%BA%E1%80%97%E1%80%BB%E1%80%B0%E1%80%9C%E1%80%AC" title="နက်ဗျူလာ – Burmese" lang="my" hreflang="my" data-title="နက်ဗျူလာ" data-language-autonym="မြန်မာဘာသာ" data-language-local-name="Burmese" class="interlanguage-link-target"><span>မြန်မာဘာသာ</span></a></li><li class="interlanguage-link interwiki-fj mw-list-item"><a href="https://fj.wikipedia.org/wiki/Nebula" title="Nebula – Fijian" lang="fj" hreflang="fj" data-title="Nebula" data-language-autonym="Na Vosa Vakaviti" data-language-local-name="Fijian" class="interlanguage-link-target"><span>Na Vosa Vakaviti</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Nevels_en_gaswolken" title="Nevels en gaswolken – Dutch" lang="nl" hreflang="nl" data-title="Nevels en gaswolken" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ne mw-list-item"><a href="https://ne.wikipedia.org/wiki/%E0%A4%A8%E0%A4%BF%E0%A4%B9%E0%A4%BE%E0%A4%B0%E0%A4%BF%E0%A4%95%E0%A4%BE" title="निहारिका – Nepali" lang="ne" hreflang="ne" data-title="निहारिका" data-language-autonym="नेपाली" data-language-local-name="Nepali" class="interlanguage-link-target"><span>नेपाली</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E6%98%9F%E9%9B%B2" title="星雲 – Japanese" lang="ja" hreflang="ja" data-title="星雲" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-nap badge-Q17437796 badge-featuredarticle mw-list-item" title="featured article badge"><a href="https://nap.wikipedia.org/wiki/N%C3%ABbb%C3%ABlosa" title="Nëbbëlosa – Neapolitan" lang="nap" hreflang="nap" data-title="Nëbbëlosa" data-language-autonym="Napulitano" data-language-local-name="Neapolitan" class="interlanguage-link-target"><span>Napulitano</span></a></li><li class="interlanguage-link interwiki-ce mw-list-item"><a href="https://ce.wikipedia.org/wiki/%D0%A2%D0%B0%D1%87%D0%B0" title="Тача – Chechen" lang="ce" hreflang="ce" data-title="Тача" data-language-autonym="Нохчийн" data-language-local-name="Chechen" class="interlanguage-link-target"><span>Нохчийн</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Stjernet%C3%A5ke" title="Stjernetåke – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Stjernetåke" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/T%C3%A5ke_i_astronomi" title="Tåke i astronomi – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Tåke i astronomi" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-nov mw-list-item"><a href="https://nov.wikipedia.org/wiki/Nebula" title="Nebula – Novial" lang="nov" hreflang="nov" data-title="Nebula" data-language-autonym="Novial" data-language-local-name="Novial" class="interlanguage-link-target"><span>Novial</span></a></li><li class="interlanguage-link interwiki-oc mw-list-item"><a href="https://oc.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Occitan" lang="oc" hreflang="oc" data-title="Nebulosa" data-language-autonym="Occitan" data-language-local-name="Occitan" class="interlanguage-link-target"><span>Occitan</span></a></li><li class="interlanguage-link interwiki-om mw-list-item"><a href="https://om.wikipedia.org/wiki/Balbala%27a" title="Balbala'a – Oromo" lang="om" hreflang="om" data-title="Balbala'a" data-language-autonym="Oromoo" data-language-local-name="Oromo" class="interlanguage-link-target"><span>Oromoo</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Tumanliklar" title="Tumanliklar – Uzbek" lang="uz" hreflang="uz" data-title="Tumanliklar" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="Uzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-pa mw-list-item"><a href="https://pa.wikipedia.org/wiki/%E0%A8%A8%E0%A9%88%E0%A8%AC%E0%A9%80%E0%A8%8A%E0%A8%B2%E0%A8%BE" title="ਨੈਬੀਊਲਾ – Punjabi" lang="pa" hreflang="pa" data-title="ਨੈਬੀਊਲਾ" data-language-autonym="ਪੰਜਾਬੀ" data-language-local-name="Punjabi" class="interlanguage-link-target"><span>ਪੰਜਾਬੀ</span></a></li><li class="interlanguage-link interwiki-pnb mw-list-item"><a href="https://pnb.wikipedia.org/wiki/%D8%A8%D8%AF%D9%84%DB%8C" title="بدلی – Western Punjabi" lang="pnb" hreflang="pnb" data-title="بدلی" data-language-autonym="پنجابی" data-language-local-name="Western Punjabi" class="interlanguage-link-target"><span>پنجابی</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Mg%C5%82awica" title="Mgławica – Polish" lang="pl" hreflang="pl" data-title="Mgławica" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Portuguese" lang="pt" hreflang="pt" data-title="Nebulosa" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Nebuloas%C4%83" title="Nebuloasă – Romanian" lang="ro" hreflang="ro" data-title="Nebuloasă" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%A2%D1%83%D0%BC%D0%B0%D0%BD%D0%BD%D0%BE%D1%81%D1%82%D1%8C" title="Туманность – Russian" lang="ru" hreflang="ru" data-title="Туманность" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-si mw-list-item"><a href="https://si.wikipedia.org/wiki/%E0%B6%B1%E0%B7%92%E0%B7%84%E0%B7%8F%E0%B6%BB%E0%B7%92%E0%B6%9A%E0%B7%8F" title="නිහාරිකා – Sinhala" lang="si" hreflang="si" data-title="නිහාරිකා" data-language-autonym="සිංහල" data-language-local-name="Sinhala" class="interlanguage-link-target"><span>සිංහල</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Nebula" title="Nebula – Simple English" lang="en-simple" hreflang="en-simple" data-title="Nebula" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Hmlovina_(astron%C3%B3mia)" title="Hmlovina (astronómia) – Slovak" lang="sk" hreflang="sk" data-title="Hmlovina (astronómia)" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Meglica" title="Meglica – Slovenian" lang="sl" hreflang="sl" data-title="Meglica" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-ckb mw-list-item"><a href="https://ckb.wikipedia.org/wiki/%D8%AA%DB%95%D9%85%DB%95%D8%B3%D8%AA%DB%8E%D8%B1%DB%95" title="تەمەستێرە – Central Kurdish" lang="ckb" hreflang="ckb" data-title="تەمەستێرە" data-language-autonym="کوردی" data-language-local-name="Central Kurdish" class="interlanguage-link-target"><span>کوردی</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%9C%D0%B0%D0%B3%D0%BB%D0%B8%D0%BD%D0%B0" title="Маглина – Serbian" lang="sr" hreflang="sr" data-title="Маглина" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Maglica" title="Maglica – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Maglica" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-su mw-list-item"><a href="https://su.wikipedia.org/wiki/N%C3%A9bula" title="Nébula – Sundanese" lang="su" hreflang="su" data-title="Nébula" data-language-autonym="Sunda" data-language-local-name="Sundanese" class="interlanguage-link-target"><span>Sunda</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Kaasusumu" title="Kaasusumu – Finnish" lang="fi" hreflang="fi" data-title="Kaasusumu" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Nebulosa" title="Nebulosa – Swedish" lang="sv" hreflang="sv" data-title="Nebulosa" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-tl mw-list-item"><a href="https://tl.wikipedia.org/wiki/Nebula" title="Nebula – Tagalog" lang="tl" hreflang="tl" data-title="Nebula" data-language-autonym="Tagalog" data-language-local-name="Tagalog" class="interlanguage-link-target"><span>Tagalog</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%A8%E0%AF%86%E0%AE%AA%E0%AF%81%E0%AE%B2%E0%AE%BE" title="நெபுலா – Tamil" lang="ta" hreflang="ta" data-title="நெபுலா" data-language-autonym="தமிழ்" data-language-local-name="Tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-kab mw-list-item"><a href="https://kab.wikipedia.org/wiki/Asignew" title="Asignew – Kabyle" lang="kab" hreflang="kab" data-title="Asignew" data-language-autonym="Taqbaylit" data-language-local-name="Kabyle" class="interlanguage-link-target"><span>Taqbaylit</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B9%80%E0%B8%99%E0%B8%9A%E0%B8%B4%E0%B8%A7%E0%B8%A5%E0%B8%B2" title="เนบิวลา – Thai" lang="th" hreflang="th" data-title="เนบิวลา" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-ti mw-list-item"><a href="https://ti.wikipedia.org/wiki/%E1%8A%94%E1%89%A1%E1%88%8B" title="ኔቡላ – Tigrinya" lang="ti" hreflang="ti" data-title="ኔቡላ" data-language-autonym="ትግርኛ" data-language-local-name="Tigrinya" class="interlanguage-link-target"><span>ትግርኛ</span></a></li><li class="interlanguage-link interwiki-tg mw-list-item"><a href="https://tg.wikipedia.org/wiki/%D0%9C%D0%B5%D2%93%D0%B2%D0%BE%D1%80%D0%B0" title="Меғвора – Tajik" lang="tg" hreflang="tg" data-title="Меғвора" data-language-autonym="Тоҷикӣ" data-language-local-name="Tajik" class="interlanguage-link-target"><span>Тоҷикӣ</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Bulutsu" title="Bulutsu – Turkish" lang="tr" hreflang="tr" data-title="Bulutsu" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%93%D0%B0%D0%BB%D0%B0%D0%BA%D1%82%D0%B8%D1%87%D0%BD%D0%B0_%D1%82%D1%83%D0%BC%D0%B0%D0%BD%D0%BD%D1%96%D1%81%D1%82%D1%8C" title="Галактична туманність – Ukrainian" lang="uk" hreflang="uk" data-title="Галактична туманність" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-ur mw-list-item"><a href="https://ur.wikipedia.org/wiki/%D8%B3%D8%AD%D8%A7%D8%A8%DB%8C%DB%81" title="سحابیہ – Urdu" lang="ur" hreflang="ur" data-title="سحابیہ" data-language-autonym="اردو" data-language-local-name="Urdu" class="interlanguage-link-target"><span>اردو</span></a></li><li class="interlanguage-link interwiki-za mw-list-item"><a href="https://za.wikipedia.org/wiki/Fwjndaundeiq" title="Fwjndaundeiq – Zhuang" lang="za" hreflang="za" data-title="Fwjndaundeiq" data-language-autonym="Vahcuengh" data-language-local-name="Zhuang" class="interlanguage-link-target"><span>Vahcuengh</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/Tinh_v%C3%A2n" title="Tinh vân – Vietnamese" lang="vi" hreflang="vi" data-title="Tinh vân" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-war mw-list-item"><a href="https://war.wikipedia.org/wiki/Nebula" title="Nebula – Waray" lang="war" hreflang="war" data-title="Nebula" data-language-autonym="Winaray" data-language-local-name="Waray" class="interlanguage-link-target"><span>Winaray</span></a></li><li class="interlanguage-link interwiki-wuu mw-list-item"><a href="https://wuu.wikipedia.org/wiki/%E6%98%9F%E4%BA%91" title="星云 – Wu" lang="wuu" hreflang="wuu" data-title="星云" data-language-autonym="吴语" data-language-local-name="Wu" class="interlanguage-link-target"><span>吴语</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%E6%98%9F%E9%9B%B2" title="星雲 – Cantonese" lang="yue" hreflang="yue" data-title="星雲" data-language-autonym="粵語" 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</div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Body of interstellar clouds</div> <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 other uses, see <a href="/wiki/Nebula_(disambiguation)" class="mw-disambig" title="Nebula (disambiguation)">Nebula (disambiguation)</a>.</div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Trifid_Nebula_by_Deddy_Dayag.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/75/Trifid_Nebula_by_Deddy_Dayag.jpg/330px-Trifid_Nebula_by_Deddy_Dayag.jpg" decoding="async" width="330" height="238" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/75/Trifid_Nebula_by_Deddy_Dayag.jpg/500px-Trifid_Nebula_by_Deddy_Dayag.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/75/Trifid_Nebula_by_Deddy_Dayag.jpg/960px-Trifid_Nebula_by_Deddy_Dayag.jpg 2x" data-file-width="3920" data-file-height="2822" /></a><figcaption>True color image of the <a href="/wiki/Trifid_Nebula" title="Trifid Nebula">Trifid Nebula</a>, showing complex gas and plasma structure</figcaption></figure> <p>A <b>nebula</b> (<a href="/wiki/Latin_language" class="mw-redirect" title="Latin language">Latin</a> for 'cloud, fog';<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> <abbr title="plural">pl.</abbr><span style="white-space:nowrap;"> <b>nebulae</b></span> or <b>nebulas</b>)<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> is a distinct luminescent part of <a href="/wiki/Interstellar_medium" title="Interstellar medium">interstellar medium</a>, which can consist of ionized, neutral, or molecular <a href="/wiki/Hydrogen" title="Hydrogen">hydrogen</a> and also <a href="/wiki/Cosmic_dust" title="Cosmic dust">cosmic dust</a>. Nebulae are often star-forming regions, such as in the <a href="/wiki/Pillars_of_Creation" title="Pillars of Creation">Pillars of Creation</a> in the <a href="/wiki/Eagle_Nebula" title="Eagle Nebula">Eagle Nebula</a>. In these regions, the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter and eventually become dense enough to form <a href="/wiki/Star" title="Star">stars</a>. The remaining material is then thought to form <a href="/wiki/Planet" title="Planet">planets</a> and other <a href="/wiki/Planetary_system" title="Planetary system">planetary system</a> objects. </p><p>Most nebulae are of vast size; some are hundreds of <a href="/wiki/Light-year" title="Light-year">light-years</a> in diameter. A nebula that is visible to the <a href="/wiki/Human_eye" title="Human eye">human eye</a> from <a href="/wiki/Earth" title="Earth">Earth</a> would appear larger, but no brighter, from close by.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> The <a href="/wiki/Orion_Nebula" title="Orion Nebula">Orion Nebula</a>, the brightest nebula in the sky and occupying an area twice the angular diameter of the full <a href="/wiki/Moon" title="Moon">Moon</a>, can be viewed with the naked eye but was missed by early astronomers.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> Although denser than the space surrounding them, most nebulae are far less dense than any <a href="/wiki/Vacuum" title="Vacuum">vacuum</a> created on Earth (10<sup>5</sup> to 10<sup>7</sup> molecules per cubic centimeter) – a nebular cloud the size of the <a href="/wiki/Earth" title="Earth">Earth</a> would have a total mass of only a few <a href="/wiki/Kilogram" title="Kilogram">kilograms</a>. Earth's air has a density of approximately 10<sup>19</sup> molecules per cubic centimeter; by contrast, the densest nebulae can have densities of 10<sup>4</sup> molecules per cubic centimeter. Many nebulae are visible due to fluorescence caused by embedded hot stars, while others are so diffused that they can be detected only with long exposures and special filters. Some nebulae are variably illuminated by <a href="/wiki/T_Tauri_star" title="T Tauri star">T Tauri</a> variable stars. </p><p>Originally, the term "nebula" was used to describe any diffused <a href="/wiki/Astronomical_object" title="Astronomical object">astronomical object</a>, including <a href="/wiki/Galaxy" title="Galaxy">galaxies</a> beyond the <a href="/wiki/Milky_Way" title="Milky Way">Milky Way</a>. The <a href="/wiki/Andromeda_Galaxy" title="Andromeda Galaxy">Andromeda Galaxy</a>, for instance, was once referred to as the <i>Andromeda Nebula</i> (and <a href="/wiki/Spiral_galaxies" class="mw-redirect" title="Spiral galaxies">spiral galaxies</a> in general as "spiral nebulae") before the true nature of galaxies was confirmed in the early 20th century by <a href="/wiki/Vesto_Slipher" title="Vesto Slipher">Vesto Slipher</a>, <a href="/wiki/Edwin_Hubble" title="Edwin Hubble">Edwin Hubble</a>, and others. Edwin Hubble discovered that most nebulae are associated with stars and illuminated by starlight. He also helped categorize nebulae based on the type of light spectra they produced.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Observational_history">Observational history</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=1" title="Edit section: Observational history"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Hs-2009-25-e-full.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b2/Hs-2009-25-e-full.jpg/250px-Hs-2009-25-e-full.jpg" decoding="async" width="220" height="262" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b2/Hs-2009-25-e-full.jpg/330px-Hs-2009-25-e-full.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b2/Hs-2009-25-e-full.jpg/500px-Hs-2009-25-e-full.jpg 2x" data-file-width="2439" data-file-height="2908" /></a><figcaption>Portion of the <a href="/wiki/Carina_Nebula" title="Carina Nebula">Carina Nebula</a></figcaption></figure> <p>Around 150 AD, <a href="/wiki/Ptolemy" title="Ptolemy">Ptolemy</a> recorded, in books VII–VIII of his <i><a href="/wiki/Almagest" title="Almagest">Almagest</a></i>, five stars that appeared nebulous. He also noted a region of nebulosity between the <a href="/wiki/Constellation" title="Constellation">constellations</a> <a href="/wiki/Ursa_Major" title="Ursa Major">Ursa Major</a> and <a href="/wiki/Leo_(constellation)" title="Leo (constellation)">Leo</a> that was not associated with any <a href="/wiki/Star" title="Star">star</a>.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> The first true nebula, as distinct from a <a href="/wiki/Star_cluster" title="Star cluster">star cluster</a>, was mentioned by the <a href="/wiki/Astronomy_in_the_medieval_Islamic_world" title="Astronomy in the medieval Islamic world">Muslim Persian astronomer</a> <a href="/wiki/Abd_al-Rahman_al-Sufi" title="Abd al-Rahman al-Sufi">Abd al-Rahman al-Sufi</a> in his <i><a href="/wiki/Book_of_Fixed_Stars" class="mw-redirect" title="Book of Fixed Stars">Book of Fixed Stars</a></i> (964).<sup id="cite_ref-Jones_10-0" class="reference"><a href="#cite_note-Jones-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> He noted "a little cloud" where the <a href="/wiki/Andromeda_Galaxy" title="Andromeda Galaxy">Andromeda Galaxy</a> is located.<sup id="cite_ref-rasqj25_11-0" class="reference"><a href="#cite_note-rasqj25-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> He also cataloged the <a href="/wiki/Omicron_Velorum_Cluster" class="mw-redirect" title="Omicron Velorum Cluster">Omicron Velorum</a> star cluster as a "nebulous star" and other nebulous objects, such as <a href="/wiki/Brocchi%27s_Cluster" title="Brocchi's Cluster">Brocchi's Cluster</a>.<sup id="cite_ref-Jones_10-1" class="reference"><a href="#cite_note-Jones-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> The <a href="/wiki/Supernovas" class="mw-redirect" title="Supernovas">supernovas</a> that created the <a href="/wiki/Crab_Nebula" title="Crab Nebula">Crab Nebula</a>, <a href="/wiki/SN_1054" title="SN 1054">SN 1054</a>, was observed by Arabic and <a href="/wiki/Chinese_astronomy" title="Chinese astronomy">Chinese astronomers</a> in 1054.<sup id="cite_ref-Lundmark_12-0" class="reference"><a href="#cite_note-Lundmark-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Mayall_13-0" class="reference"><a href="#cite_note-Mayall-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p><p>In 1610, <a href="/wiki/Nicolas-Claude_Fabri_de_Peiresc" title="Nicolas-Claude Fabri de Peiresc">Nicolas-Claude Fabri de Peiresc</a> discovered the <a href="/wiki/Orion_Nebula" title="Orion Nebula">Orion Nebula</a> using a telescope. This nebula was also observed by <a href="/wiki/Johann_Baptist_Cysat" title="Johann Baptist Cysat">Johann Baptist Cysat</a> in 1618. However, the first detailed study of the Orion Nebula was not performed until 1659 by <a href="/wiki/Christiaan_Huygens" title="Christiaan Huygens">Christiaan Huygens</a>, who also believed he was the first person to discover this nebulosity.<sup id="cite_ref-rasqj25_11-1" class="reference"><a href="#cite_note-rasqj25-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p><p>In 1715, <a href="/wiki/Edmond_Halley" title="Edmond Halley">Edmond Halley</a> published a list of six nebulae.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> This number steadily increased during the century, with <a href="/wiki/Jean-Philippe_de_Cheseaux" class="mw-redirect" title="Jean-Philippe de Cheseaux">Jean-Philippe de Cheseaux</a> compiling a list of 20 (including eight not previously known) in 1746. From 1751 to 1753, <a href="/wiki/Nicolas-Louis_de_Lacaille" title="Nicolas-Louis de Lacaille">Nicolas-Louis de Lacaille</a> cataloged 42 nebulae from the <a href="/wiki/Cape_of_Good_Hope" title="Cape of Good Hope">Cape of Good Hope</a>, most of which were previously unknown. <a href="/wiki/Charles_Messier" title="Charles Messier">Charles Messier</a> then compiled a catalog of 103 "nebulae" (now called <a href="/wiki/Messier_object" title="Messier object">Messier objects</a>, which included what are now known to be galaxies) by 1781; his interest was detecting <a href="/wiki/Comet" title="Comet">comets</a>, and these were objects that might be mistaken for them.<sup id="cite_ref-hoskin2005_15-0" class="reference"><a href="#cite_note-hoskin2005-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>The number of nebulae was then greatly increased by the efforts of <a href="/wiki/William_Herschel" title="William Herschel">William Herschel</a> and his sister, <a href="/wiki/Caroline_Herschel" title="Caroline Herschel">Caroline Herschel</a>. Their <i>Catalogue of One Thousand New Nebulae and Clusters of Stars</i><sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> was published in 1786. A second catalog of a thousand was published in 1789, and the third and final catalog of 510 appeared in 1802. During much of their work, William Herschel believed that these nebulae were merely unresolved clusters of stars. In 1790, however, he discovered a star surrounded by nebulosity and concluded that this was a true nebulosity rather than a more distant cluster.<sup id="cite_ref-hoskin2005_15-1" class="reference"><a href="#cite_note-hoskin2005-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>Beginning in 1864, <a href="/wiki/William_Huggins" title="William Huggins">William Huggins</a> examined the spectra of about 70 nebulae. He found that roughly a third of them had the <a href="/wiki/Emission_spectrum" title="Emission spectrum">emission spectrum</a> of a <a href="/wiki/Gas" title="Gas">gas</a>. The rest showed a continuous spectrum and were thus thought to consist of a mass of stars.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-struve37_18-0" class="reference"><a href="#cite_note-struve37-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> A third category was added in 1912 when <a href="/wiki/Vesto_Slipher" title="Vesto Slipher">Vesto Slipher</a> showed that the spectrum of the nebula that surrounded the star <a href="/wiki/Merope_(star)" title="Merope (star)">Merope</a> matched the spectra of the <a href="/wiki/Pleiades" title="Pleiades">Pleiades</a> <a href="/wiki/Open_cluster" title="Open cluster">open cluster</a>. Thus, the nebula radiates by reflected star light.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> </p><p>In 1923, following the <a href="/wiki/Great_Debate_(astronomy)" title="Great Debate (astronomy)">Great Debate</a>, it became clear that many "nebulae" were in fact galaxies far from the <a href="/wiki/Milky_Way" title="Milky Way">Milky Way</a>. </p><p>Slipher and <a href="/wiki/Edwin_Hubble" title="Edwin Hubble">Edwin Hubble</a> continued to collect the spectra from many different nebulae, finding 29 that showed emission spectra and 33 that had the continuous spectra of star light.<sup id="cite_ref-struve37_18-1" class="reference"><a href="#cite_note-struve37-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> In 1922, Hubble announced that nearly all nebulae are associated with stars and that their illumination comes from star light. He also discovered that the emission spectrum nebulae are nearly always associated with stars having spectral classifications of B or hotter (including all <a href="/wiki/O-type_main_sequence_star" class="mw-redirect" title="O-type main sequence star">O-type main sequence stars</a>), while nebulae with continuous spectra appear with cooler stars.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> Both Hubble and <a href="/wiki/Henry_Norris_Russell" title="Henry Norris Russell">Henry Norris Russell</a> concluded that the nebulae surrounding the hotter stars are transformed in some manner.<sup id="cite_ref-struve37_18-2" class="reference"><a href="#cite_note-struve37-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Formation">Formation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=2" title="Edit section: Formation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Nursery_of_New_Stars_-_GPN-2000-000972.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/7a/Nursery_of_New_Stars_-_GPN-2000-000972.jpg/220px-Nursery_of_New_Stars_-_GPN-2000-000972.jpg" decoding="async" width="220" height="234" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/7a/Nursery_of_New_Stars_-_GPN-2000-000972.jpg/330px-Nursery_of_New_Stars_-_GPN-2000-000972.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/7a/Nursery_of_New_Stars_-_GPN-2000-000972.jpg/440px-Nursery_of_New_Stars_-_GPN-2000-000972.jpg 2x" data-file-width="1127" data-file-height="1201" /></a><figcaption><a href="/wiki/NGC_604" title="NGC 604">NGC 604</a>, a nebula in the <a href="/wiki/Triangulum_Galaxy" title="Triangulum Galaxy">Triangulum Galaxy</a></figcaption></figure> <p>There are a variety of formation mechanisms for the different types of nebulae. Some nebulae form from gas that is already in the <a href="/wiki/Interstellar_medium" title="Interstellar medium">interstellar medium</a> while others are produced by stars. Examples of the former case are <a href="/wiki/Giant_molecular_clouds" class="mw-redirect" title="Giant molecular clouds">giant molecular clouds</a>, the coldest, densest phase of interstellar gas, which can form by the cooling and condensation of more diffuse gas. Examples of the latter case are planetary nebulae formed from material shed by a star in late stages of its <a href="/wiki/Stellar_evolution" title="Stellar evolution">stellar evolution</a>. </p><p><a href="/wiki/Star-forming_region" class="mw-redirect" title="Star-forming region">Star-forming regions</a> are a class of emission nebula associated with giant molecular clouds. These form as a molecular cloud collapses under its own weight, producing stars. Massive stars may form in the center, and their <a href="/wiki/Ultraviolet_radiation" class="mw-redirect" title="Ultraviolet radiation">ultraviolet radiation</a> <a href="/wiki/Ion" title="Ion">ionizes</a> the surrounding gas, making it visible at optical <a href="/wiki/Wavelength" title="Wavelength">wavelengths</a>. The region of ionized hydrogen surrounding the massive stars is known as an <a href="/wiki/H_II_region" title="H II region">H II region</a> while the shells of neutral hydrogen surrounding the H II region are known as <a href="/wiki/Photodissociation_region" title="Photodissociation region">photodissociation region</a>. Examples of star-forming regions are the <a href="/wiki/Orion_Nebula" title="Orion Nebula">Orion Nebula</a>, the <a href="/wiki/Rosette_Nebula" title="Rosette Nebula">Rosette Nebula</a> and the <a href="/wiki/Omega_Nebula" title="Omega Nebula">Omega Nebula</a>. Feedback from star-formation, in the form of supernova explosions of massive stars, stellar winds or ultraviolet radiation from massive stars, or outflows from low-mass stars may disrupt the cloud, destroying the nebula after several million years. </p><p>Other nebulae form as the result of <a href="/wiki/Supernova" title="Supernova">supernova</a> explosions; the death throes of massive, short-lived stars. The materials thrown off from the supernova explosion are then ionized by the energy and the compact object that its core produces. One of the best examples of this is the <a href="/wiki/Crab_Nebula" title="Crab Nebula">Crab Nebula</a>, in <a href="/wiki/Taurus_(constellation)" title="Taurus (constellation)">Taurus</a>. The supernova event was recorded in the year 1054 and is labeled <a href="/wiki/SN_1054" title="SN 1054">SN 1054</a>. The compact object that was created after the explosion lies in the center of the Crab Nebula and its core is now a <a href="/wiki/Neutron_star" title="Neutron star">neutron star</a>. </p><p>Still other nebulae form as <a href="/wiki/Planetary_nebulae" class="mw-redirect" title="Planetary nebulae">planetary nebulae</a>. This is the final stage of a low-mass star's life, like Earth's Sun. Stars with a mass up to 8–10 solar masses evolve into <a href="/wiki/Red_giant" title="Red giant">red giants</a> and slowly lose their outer layers during pulsations in their atmospheres. When a star has lost enough material, its temperature increases and the <a href="/wiki/Ultraviolet_radiation" class="mw-redirect" title="Ultraviolet radiation">ultraviolet radiation</a> it emits can <a href="/wiki/Ion" title="Ion">ionize</a> the surrounding nebula that it has thrown off. The Sun will produce a planetary nebula and its core will remain behind in the form of a <a href="/wiki/White_dwarf" title="White dwarf">white dwarf</a>. </p> <div style="clear:both;" class=""></div> <div class="mw-heading mw-heading2"><h2 id="Types">Types</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=3" title="Edit section: Types"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul class="gallery mw-gallery-packed center"> <li class="gallerybox" style="width: 230px"> <div class="thumb" style="width: 228px;"><span typeof="mw:File"><a href="/wiki/File:Hubble_Sees_a_Stellar_%22Sneezing_Fit%22_(11467249715).jpg" class="mw-file-description" title="Herbig–Haro HH 161 and HH 164.[21]"><img alt="Herbig–Haro HH 161 and HH 164.[21]" src="//upload.wikimedia.org/wikipedia/commons/thumb/2/27/Hubble_Sees_a_Stellar_%22Sneezing_Fit%22_%2811467249715%29.jpg/342px-Hubble_Sees_a_Stellar_%22Sneezing_Fit%22_%2811467249715%29.jpg" decoding="async" width="228" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/27/Hubble_Sees_a_Stellar_%22Sneezing_Fit%22_%2811467249715%29.jpg/513px-Hubble_Sees_a_Stellar_%22Sneezing_Fit%22_%2811467249715%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/27/Hubble_Sees_a_Stellar_%22Sneezing_Fit%22_%2811467249715%29.jpg/684px-Hubble_Sees_a_Stellar_%22Sneezing_Fit%22_%2811467249715%29.jpg 2x" data-file-width="1280" data-file-height="674" /></a></span></div> <div class="gallerytext"><a href="/wiki/Herbig%E2%80%93Haro_object" title="Herbig–Haro object">Herbig–Haro</a> <a href="/w/index.php?title=HH_161&action=edit&redlink=1" class="new" title="HH 161 (page does not exist)">HH 161</a> and <a href="/w/index.php?title=HH_164&action=edit&redlink=1" class="new" title="HH 164 (page does not exist)">HH 164</a>.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup></div> </li> <li class="gallerybox" style="width: 150px"> <div class="thumb" style="width: 148px;"><span typeof="mw:File"><a href="/wiki/File:Omega_Nebula.jpg" class="mw-file-description" title="The Omega Nebula, an example of an emission nebula"><img alt="The Omega Nebula, an example of an emission nebula" src="//upload.wikimedia.org/wikipedia/commons/thumb/7/72/Omega_Nebula.jpg/222px-Omega_Nebula.jpg" decoding="async" width="148" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/72/Omega_Nebula.jpg/333px-Omega_Nebula.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/72/Omega_Nebula.jpg/444px-Omega_Nebula.jpg 2x" data-file-width="2163" data-file-height="1756" /></a></span></div> <div class="gallerytext">The <a href="/wiki/Omega_Nebula" title="Omega Nebula">Omega Nebula</a>, an example of an <a href="/wiki/Emission_nebula" title="Emission nebula">emission nebula</a></div> </li> <li class="gallerybox" style="width: 167.33333333333px"> <div class="thumb" style="width: 165.33333333333px;"><span typeof="mw:File"><a href="/wiki/File:Horsehead-Hubble.jpg" class="mw-file-description" title="The Horsehead Nebula, an example of a dark nebula."><img alt="The Horsehead Nebula, an example of a dark nebula." src="//upload.wikimedia.org/wikipedia/commons/thumb/4/46/Horsehead-Hubble.jpg/248px-Horsehead-Hubble.jpg" decoding="async" width="166" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/46/Horsehead-Hubble.jpg/371px-Horsehead-Hubble.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/46/Horsehead-Hubble.jpg/495px-Horsehead-Hubble.jpg 2x" data-file-width="2839" data-file-height="2065" /></a></span></div> <div class="gallerytext">The <a href="/wiki/Horsehead_Nebula" title="Horsehead Nebula">Horsehead Nebula</a>, an example of a <a href="/wiki/Dark_nebula" title="Dark nebula">dark nebula</a>.</div> </li> <li class="gallerybox" style="width: 122px"> <div class="thumb" style="width: 120px;"><span typeof="mw:File"><a href="/wiki/File:NGC6543.jpg" class="mw-file-description" title="The Cat's Eye Nebula, an example of a planetary nebula."><img alt="The Cat's Eye Nebula, an example of a planetary nebula." src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5a/NGC6543.jpg/250px-NGC6543.jpg" decoding="async" width="120" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5a/NGC6543.jpg/330px-NGC6543.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5a/NGC6543.jpg/500px-NGC6543.jpg 2x" data-file-width="2100" data-file-height="2100" /></a></span></div> <div class="gallerytext">The <a href="/wiki/Cat%27s_Eye_Nebula" title="Cat's Eye Nebula">Cat's Eye Nebula</a>, an example of a <a href="/wiki/Planetary_nebula" title="Planetary nebula">planetary nebula</a>.</div> </li> <li class="gallerybox" style="width: 122px"> <div class="thumb" style="width: 120px;"><span typeof="mw:File"><a href="/wiki/File:PIA04533.jpg" class="mw-file-description" title="The Red Rectangle Nebula, an example of a protoplanetary nebula."><img alt="The Red Rectangle Nebula, an example of a protoplanetary nebula." src="//upload.wikimedia.org/wikipedia/commons/thumb/4/43/PIA04533.jpg/180px-PIA04533.jpg" decoding="async" width="120" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/43/PIA04533.jpg/270px-PIA04533.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/43/PIA04533.jpg/359px-PIA04533.jpg 2x" data-file-width="583" data-file-height="584" /></a></span></div> <div class="gallerytext">The <a href="/wiki/Red_Rectangle_Nebula" title="Red Rectangle Nebula">Red Rectangle Nebula</a>, an example of a <a href="/wiki/Protoplanetary_nebula" title="Protoplanetary nebula">protoplanetary nebula</a>.</div> </li> <li class="gallerybox" style="width: 122px"> <div class="thumb" style="width: 120px;"><span typeof="mw:File"><a href="/wiki/File:SNR_0509.jpg" class="mw-file-description" title="The delicate shell of SNR B0509-67.5"><img alt="The delicate shell of SNR B0509-67.5" src="//upload.wikimedia.org/wikipedia/commons/thumb/9/9e/SNR_0509.jpg/180px-SNR_0509.jpg" decoding="async" width="120" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/9e/SNR_0509.jpg/270px-SNR_0509.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/9e/SNR_0509.jpg/360px-SNR_0509.jpg 2x" data-file-width="2000" data-file-height="2000" /></a></span></div> <div class="gallerytext">The delicate shell of <a href="/wiki/SNR_0509-67.5" title="SNR 0509-67.5">SNR B0509-67.5</a></div> </li> <li class="gallerybox" style="width: 154px"> <div class="thumb" style="width: 152px;"><span typeof="mw:File"><a href="/wiki/File:Tycho_xrayonly.jpg" class="mw-file-description" title="Tycho Supernova remnant in X-ray light"><img alt="Tycho Supernova remnant in X-ray light" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/46/Tycho_xrayonly.jpg/250px-Tycho_xrayonly.jpg" decoding="async" width="152" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/46/Tycho_xrayonly.jpg/500px-Tycho_xrayonly.jpg 1.5x" data-file-width="864" data-file-height="683" /></a></span></div> <div class="gallerytext"><a href="/wiki/SN_1572" title="SN 1572">Tycho Supernova remnant in X-ray light</a></div> </li> <li class="gallerybox" style="width: 130.66666666667px"> <div class="thumb" style="width: 128.66666666667px;"><span typeof="mw:File"><a href="/wiki/File:Southern_Ring_Nebula_by_Webb_Telescope_(2022).jpg" class="mw-file-description" title="Southern Ring Nebula, Planetary Nebula"><img alt="Southern Ring Nebula, Planetary Nebula" src="//upload.wikimedia.org/wikipedia/commons/thumb/2/21/Southern_Ring_Nebula_by_Webb_Telescope_%282022%29.jpg/250px-Southern_Ring_Nebula_by_Webb_Telescope_%282022%29.jpg" decoding="async" width="129" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/21/Southern_Ring_Nebula_by_Webb_Telescope_%282022%29.jpg/330px-Southern_Ring_Nebula_by_Webb_Telescope_%282022%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/21/Southern_Ring_Nebula_by_Webb_Telescope_%282022%29.jpg/500px-Southern_Ring_Nebula_by_Webb_Telescope_%282022%29.jpg 2x" data-file-width="4833" data-file-height="4501" /></a></span></div> <div class="gallerytext"><a href="/wiki/NGC_3132" title="NGC 3132">Southern Ring Nebula</a>, Planetary Nebula</div> </li> <li class="gallerybox" style="width: 145.33333333333px"> <div class="thumb" style="width: 143.33333333333px;"><span typeof="mw:File"><a href="/wiki/File:Webb_captures_detailed_beauty_of_Ring_Nebula_(NIRCam_and_MIRI_images)_(weic2320a).jpg" class="mw-file-description" title="Ring Nebula in the northern constellation of Lyra"><img alt="Ring Nebula in the northern constellation of Lyra" src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Webb_captures_detailed_beauty_of_Ring_Nebula_%28NIRCam_and_MIRI_images%29_%28weic2320a%29.jpg/250px-Webb_captures_detailed_beauty_of_Ring_Nebula_%28NIRCam_and_MIRI_images%29_%28weic2320a%29.jpg" decoding="async" width="144" height="120" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Webb_captures_detailed_beauty_of_Ring_Nebula_%28NIRCam_and_MIRI_images%29_%28weic2320a%29.jpg/330px-Webb_captures_detailed_beauty_of_Ring_Nebula_%28NIRCam_and_MIRI_images%29_%28weic2320a%29.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Webb_captures_detailed_beauty_of_Ring_Nebula_%28NIRCam_and_MIRI_images%29_%28weic2320a%29.jpg/500px-Webb_captures_detailed_beauty_of_Ring_Nebula_%28NIRCam_and_MIRI_images%29_%28weic2320a%29.jpg 2x" data-file-width="4097" data-file-height="3428" /></a></span></div> <div class="gallerytext"><a href="/wiki/Ring_Nebula" title="Ring Nebula">Ring Nebula</a> in the northern constellation of <a href="/wiki/Lyra" title="Lyra">Lyra</a></div> </li> </ul> <div class="mw-heading mw-heading3"><h3 id="Classical_types">Classical types</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=4" title="Edit section: Classical types"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Objects named nebulae belong to four major groups. Before their nature was understood, <a href="/wiki/Galaxy" title="Galaxy">galaxies</a> ("spiral nebulae") and <a href="/wiki/Star_cluster" title="Star cluster">star clusters</a> too distant to be resolved as stars were also classified as nebulae, but no longer are. </p> <ul><li><a href="/wiki/H_II_region" title="H II region">H II regions</a>, large diffuse nebulae containing ionized hydrogen</li> <li><a href="/wiki/Planetary_nebula" title="Planetary nebula">Planetary nebulae</a></li> <li><a href="/wiki/Supernova_remnant" title="Supernova remnant">Supernova remnants</a> (e.g., Crab Nebula)</li> <li><a href="/wiki/Dark_nebula" title="Dark nebula">Dark nebulae</a></li></ul> <p>Not all cloud-like structures are nebulae; <a href="/wiki/Herbig%E2%80%93Haro_object" title="Herbig–Haro object">Herbig–Haro objects</a> are an example. </p> <div class="mw-heading mw-heading3"><h3 id="Flux_Nebulae">Flux Nebulae</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=5" title="Edit section: Flux Nebulae"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Integrated_Flux_Nebula" title="Integrated Flux Nebula">Integrated Flux Nebula</a></div> <div class="excerpt-block"><style data-mw-deduplicate="TemplateStyles:r1066933788">.mw-parser-output .excerpt-hat .mw-editsection-like{font-style:normal}</style><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable dablink excerpt-hat selfref">This section is an excerpt from <a href="/wiki/Integrated_Flux_Nebula" title="Integrated Flux Nebula">Integrated Flux Nebula</a>.<span class="mw-editsection-like plainlinks"><span class="mw-editsection-bracket">[</span><a class="external text" href="https://en.wikipedia.org/w/index.php?title=Integrated_Flux_Nebula&action=edit">edit</a><span class="mw-editsection-bracket">]</span></span></div><div class="excerpt"> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Integrated_Flux_Nebula_Surrounding_Polaris_-_Kush_Chandaria.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/10/Integrated_Flux_Nebula_Surrounding_Polaris_-_Kush_Chandaria.jpg/220px-Integrated_Flux_Nebula_Surrounding_Polaris_-_Kush_Chandaria.jpg" decoding="async" width="220" height="140" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/10/Integrated_Flux_Nebula_Surrounding_Polaris_-_Kush_Chandaria.jpg/330px-Integrated_Flux_Nebula_Surrounding_Polaris_-_Kush_Chandaria.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/10/Integrated_Flux_Nebula_Surrounding_Polaris_-_Kush_Chandaria.jpg/440px-Integrated_Flux_Nebula_Surrounding_Polaris_-_Kush_Chandaria.jpg 2x" data-file-width="2000" data-file-height="1270" /></a><figcaption>An example of faint integrated flux nebula surrounding the star <a href="/wiki/Polaris" title="Polaris">Polaris</a></figcaption></figure> <p><a href="/wiki/Integrated_Flux_Nebula" title="Integrated Flux Nebula">Integrated flux nebulae</a> are a relatively recently identified astronomical phenomenon. In contrast to the typical and well known gaseous nebulae within the plane of the <a href="/wiki/Milky_Way" title="Milky Way">Milky Way</a> <a href="/wiki/Galaxy" title="Galaxy">galaxy</a>, IFNs lie beyond the main body of the galaxy. </p> The term was coined by <a href="/wiki/Steve_Mandel" title="Steve Mandel">Steve Mandel</a> who defined them as "high galactic latitude nebula that are illuminated not by a single star (as most nebula in the plane of the Galaxy are) but by the energy from the integrated flux of all the stars in the Milky Way. As a result, these nebulae are incredibly faint, taking hours of exposure to capture. These nebulae clouds, an important component of the interstellar medium, are composed of dust particles, hydrogen and carbon monoxide and some other elements."<sup id="cite_ref-Integrated_Flux_Nebula_:0_22-0" class="reference"><a href="#cite_note-Integrated_Flux_Nebula_:0-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> They are particularly prominent in the direction of both the north and south <a href="/wiki/Celestial_pole" title="Celestial pole">celestial poles</a>. The vast nebula close to the south celestial pole is MW9, commonly known as the South Celestial Serpent.<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup></div></div> <div class="mw-heading mw-heading3"><h3 id="Diffuse_nebulae">Diffuse nebulae</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=6" title="Edit section: Diffuse nebulae"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Carina_Nebula_by_ESO.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/20/Carina_Nebula_by_ESO.jpg/220px-Carina_Nebula_by_ESO.jpg" decoding="async" width="220" height="218" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/20/Carina_Nebula_by_ESO.jpg/330px-Carina_Nebula_by_ESO.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/20/Carina_Nebula_by_ESO.jpg/440px-Carina_Nebula_by_ESO.jpg 2x" data-file-width="8408" data-file-height="8337" /></a><figcaption>The Carina Nebula is an example of a diffuse nebula</figcaption></figure> <p>Most nebulae can be described as diffuse nebulae, which means that they are extended and contain no well-defined boundaries.<sup id="cite_ref-Messier_24-0" class="reference"><a href="#cite_note-Messier-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> Diffuse nebulae can be divided into <a href="/wiki/Emission_nebula" title="Emission nebula">emission nebulae</a>, <a href="/wiki/Reflection_nebula" title="Reflection nebula">reflection nebulae</a> and <a href="/wiki/Dark_nebula" title="Dark nebula">dark nebulae</a>. </p><p>Visible light nebulae may be divided into emission nebulae, which emit <a href="/wiki/Spectral_line" title="Spectral line">spectral line</a> radiation from excited or <a href="/wiki/Ion" title="Ion">ionized</a> gas (mostly ionized <a href="/wiki/Hydrogen" title="Hydrogen">hydrogen</a>);<sup id="cite_ref-shu1982_25-0" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> they are often called <a href="/wiki/H_II_region" title="H II region">H II regions</a>, H II referring to ionized hydrogen), and reflection nebulae which are visible primarily due to the light they reflect. </p><p>Reflection nebulae themselves do not emit significant amounts of visible light, but are near stars and reflect light from them.<sup id="cite_ref-shu1982_25-1" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> Similar nebulae not illuminated by stars do not exhibit visible radiation, but may be detected as opaque clouds blocking light from luminous objects behind them; they are called <a href="/wiki/Dark_nebula" title="Dark nebula">dark nebulae</a>.<sup id="cite_ref-shu1982_25-2" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> </p><p>Although these nebulae have different visibility at optical wavelengths, they are all bright sources of <a href="/wiki/Infrared" title="Infrared">infrared</a> emission, chiefly from <a href="/wiki/Cosmic_dust" title="Cosmic dust">dust</a> within the nebulae.<sup id="cite_ref-shu1982_25-3" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Planetary_nebulae">Planetary nebulae</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=7" title="Edit section: Planetary nebulae"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Planetary_nebula" title="Planetary nebula">Planetary nebula</a></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:A_hazy_nebula.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/A_hazy_nebula.jpg/250px-A_hazy_nebula.jpg" decoding="async" width="220" height="218" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/A_hazy_nebula.jpg/330px-A_hazy_nebula.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/aa/A_hazy_nebula.jpg/500px-A_hazy_nebula.jpg 2x" data-file-width="1280" data-file-height="1270" /></a><figcaption>The <a href="/wiki/NGC_1501" title="NGC 1501">Oyster Nebula</a> is a <a href="/wiki/Planetary_nebula" title="Planetary nebula">planetary nebula</a> located in the constellation of <a href="/wiki/Camelopardalis" title="Camelopardalis">Camelopardalis</a></figcaption></figure> <p>Planetary nebulae are the remnants of the final stages of stellar evolution for mid-mass stars (varying in size between 0.5-~8 solar masses). Evolved <a href="/wiki/Asymptotic_giant_branch" title="Asymptotic giant branch">asymptotic giant branch</a> stars expel their outer layers outwards due to strong stellar winds, thus forming gaseous shells while leaving behind the star's core in the form of a <a href="/wiki/White_dwarf" title="White dwarf">white dwarf</a>.<sup id="cite_ref-shu1982_25-4" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> Radiation from the hot white dwarf excites the expelled gases, producing emission nebulae with spectra similar to those of emission nebulae found in <a href="/wiki/Star_formation" title="Star formation">star formation</a> regions.<sup id="cite_ref-shu1982_25-5" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> They are <a href="/wiki/H_II_region" title="H II region">H II regions</a>, because mostly hydrogen is ionized, but planetary are denser and more compact than nebulae found in star formation regions.<sup id="cite_ref-shu1982_25-6" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> </p><p>Planetary nebulae were given their name by the first astronomical observers who were initially unable to distinguish them from planets, which were of more interest to them. The Sun is expected to spawn a planetary nebula about 12 billion years after its formation.<sup id="cite_ref-s_26-0" class="reference"><a href="#cite_note-s-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading4"><h4 id="Protoplanetary_nebulae">Protoplanetary nebulae</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=8" title="Edit section: Protoplanetary nebulae"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Protoplanetary_nebula" title="Protoplanetary nebula">Protoplanetary nebula</a></div> <div class="excerpt-block"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1066933788" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951" /><div role="note" class="hatnote navigation-not-searchable dablink excerpt-hat selfref">This section is an excerpt from <a href="/wiki/Protoplanetary_nebula" title="Protoplanetary nebula">Protoplanetary nebula</a>.<span class="mw-editsection-like plainlinks"><span class="mw-editsection-bracket">[</span><a class="external text" href="https://en.wikipedia.org/w/index.php?title=Protoplanetary_nebula&action=edit">edit</a><span class="mw-editsection-bracket">]</span></span></div><div class="excerpt"> <figure class="mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Westbrook_Nebula.tif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Westbrook_Nebula.tif/lossy-page1-250px-Westbrook_Nebula.tif.jpg" decoding="async" width="250" height="250" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Westbrook_Nebula.tif/lossy-page1-375px-Westbrook_Nebula.tif.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Westbrook_Nebula.tif/lossy-page1-500px-Westbrook_Nebula.tif.jpg 2x" data-file-width="1000" data-file-height="1000" /></a><figcaption>The <a href="/wiki/Westbrook_Nebula" title="Westbrook Nebula">Westbrook Nebula</a>, a protoplanetary nebula.</figcaption></figure> A <a href="/wiki/Protoplanetary_nebula" title="Protoplanetary nebula">protoplanetary nebula</a> or preplanetary nebula<sup id="cite_ref-Protoplanetary_nebula_Sahai_&_Sanchez_Contreras_et_al_2005_27-0" class="reference"><a href="#cite_note-Protoplanetary_nebula_Sahai_&_Sanchez_Contreras_et_al_2005-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> (PPN, plural PPNe) is an <a href="/wiki/Astronomical_object" title="Astronomical object">astronomical object</a> which is at the short-lived episode during a <a href="/wiki/Star" title="Star">star</a>'s rapid <a href="/wiki/Stellar_evolution" title="Stellar evolution">evolution</a> between the late <a href="/wiki/Asymptotic_giant_branch" title="Asymptotic giant branch">asymptotic giant branch</a> (LAGB)<style data-mw-deduplicate="TemplateStyles:r1041539562">.mw-parser-output .citation{word-wrap:break-word}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}</style><sup class="citation nobold" id="ref_Anone"><a href="#endnote_Anone">[a]</a></sup> phase and the subsequent <a href="/wiki/Planetary_nebula" title="Planetary nebula">planetary nebula</a> (PN) phase. A PPN emits strongly in <a href="/wiki/Infrared" title="Infrared">infrared</a> radiation, and is a kind of <a href="/wiki/Reflection_nebula" title="Reflection nebula">reflection nebula</a>. It is the second-from-the-last high-luminosity evolution phase in the life cycle of intermediate-mass stars (1–8 <a href="/wiki/Solar_mass" title="Solar mass"><var>M</var><sub>☉</sub></a>).<sup id="cite_ref-Protoplanetary_nebula_Kastner2005_28-0" class="reference"><a href="#cite_note-Protoplanetary_nebula_Kastner2005-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup><sup class="reference nowrap"><span title="Page / location: 469">: 469 </span></sup></div></div> <div class="mw-heading mw-heading3"><h3 id="Supernova_remnants">Supernova remnants</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=9" title="Edit section: Supernova remnants"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Crab_Nebula.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/250px-Crab_Nebula.jpg" decoding="async" width="220" height="220" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/330px-Crab_Nebula.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/500px-Crab_Nebula.jpg 2x" data-file-width="3864" data-file-height="3864" /></a><figcaption>The <a href="/wiki/Crab_Nebula" title="Crab Nebula">Crab Nebula</a>, an example of a <a href="/wiki/Supernova_remnant" title="Supernova remnant">supernova remnant</a></figcaption></figure> <p>A <a href="/wiki/Supernova" title="Supernova">supernova</a> occurs when a high-mass star reaches the end of its life. When <a href="/wiki/Nuclear_fusion" title="Nuclear fusion">nuclear fusion</a> in the core of the star stops, the star collapses. The gas falling inward either rebounds or gets so strongly heated that it expands outwards from the core, thus causing the star to explode.<sup id="cite_ref-shu1982_25-7" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> The expanding shell of gas forms a <a href="/wiki/Supernova_remnant" title="Supernova remnant">supernova remnant</a>, a special <a href="/wiki/Diffuse_nebula" class="mw-redirect" title="Diffuse nebula">diffuse nebula</a>.<sup id="cite_ref-shu1982_25-8" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> Although much of the optical and <a href="/wiki/X-ray" title="X-ray">X-ray</a> emission from supernova remnants originates from ionized gas, a great amount of the <a href="/wiki/Radio_wave" title="Radio wave">radio</a> emission is a form of non-thermal emission called <a href="/wiki/Synchrotron_emission" class="mw-redirect" title="Synchrotron emission">synchrotron emission</a>.<sup id="cite_ref-shu1982_25-9" class="reference"><a href="#cite_note-shu1982-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> This emission originates from high-velocity <a href="/wiki/Electron" title="Electron">electrons</a> oscillating within <a href="/wiki/Magnetic_field" title="Magnetic field">magnetic fields</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Examples">Examples</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=10" title="Edit section: Examples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1184024115">.mw-parser-output .div-col{margin-top:0.3em;column-width:30em}.mw-parser-output .div-col-small{font-size:90%}.mw-parser-output .div-col-rules{column-rule:1px solid #aaa}.mw-parser-output .div-col dl,.mw-parser-output .div-col ol,.mw-parser-output .div-col ul{margin-top:0}.mw-parser-output .div-col li,.mw-parser-output .div-col dd{page-break-inside:avoid;break-inside:avoid-column}</style><div class="div-col" style="column-width: 18em;"> <ul><li><a href="/wiki/Ant_Nebula" class="mw-redirect" title="Ant Nebula">Ant Nebula</a></li> <li><a href="/wiki/Barnard%27s_Loop" title="Barnard's Loop">Barnard's Loop</a></li> <li><a href="/wiki/Boomerang_Nebula" title="Boomerang Nebula">Boomerang Nebula</a></li> <li><a href="/wiki/Cat%27s_Eye_Nebula" title="Cat's Eye Nebula">Cat's Eye Nebula</a></li> <li><a href="/wiki/Crab_Nebula" title="Crab Nebula">Crab Nebula</a></li> <li><a href="/wiki/Eagle_Nebula" title="Eagle Nebula">Eagle Nebula</a></li> <li><a href="/wiki/Eskimo_Nebula" title="Eskimo Nebula">Eskimo Nebula</a></li> <li><a href="/wiki/Carina_Nebula" title="Carina Nebula">Carina Nebula</a></li> <li><a href="/wiki/Fox_Fur_Nebula" title="Fox Fur Nebula">Fox Fur Nebula</a></li> <li><a href="/wiki/Helix_Nebula" title="Helix Nebula">Helix Nebula</a></li> <li><a href="/wiki/Horsehead_Nebula" title="Horsehead Nebula">Horsehead Nebula</a></li> <li><a href="/wiki/Engraved_Hourglass_Nebula" title="Engraved Hourglass Nebula">Engraved Hourglass Nebula</a></li> <li><a href="/wiki/Lagoon_Nebula" title="Lagoon Nebula">Lagoon Nebula</a></li> <li><a href="/wiki/Orion_Nebula" title="Orion Nebula">Orion Nebula</a></li> <li><a href="/wiki/Pelican_Nebula" title="Pelican Nebula">Pelican Nebula</a></li> <li><a href="/wiki/Red_Square_Nebula" title="Red Square Nebula">Red Square Nebula</a></li> <li><a href="/wiki/Ring_Nebula" title="Ring Nebula">Ring Nebula</a></li> <li><a href="/wiki/Rosette_Nebula" title="Rosette Nebula">Rosette Nebula</a></li> <li><a href="/wiki/Tarantula_Nebula" title="Tarantula Nebula">Tarantula Nebula</a></li> <li><a href="/w/index.php?title=Waterfall_Nebula&action=edit&redlink=1" class="new" title="Waterfall Nebula (page does not exist)">Waterfall Nebula</a></li></ul> </div> <div class="mw-heading mw-heading3"><h3 id="Catalogs">Catalogs</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=11" title="Edit section: Catalogs"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Gum_catalog" title="Gum catalog">Gum catalog</a> (emission nebulae)</li> <li><a href="/wiki/RCW_Catalogue" title="RCW Catalogue">RCW Catalogue</a> (emission nebulae)</li> <li><a href="/wiki/Sharpless_catalog" title="Sharpless catalog">Sharpless catalog</a> (emission nebulae)</li> <li><a href="/wiki/Messier_Catalogue" class="mw-redirect" title="Messier Catalogue">Messier Catalogue</a></li> <li><a href="/wiki/Caldwell_Catalogue" class="mw-redirect" title="Caldwell Catalogue">Caldwell Catalogue</a></li> <li><a href="/wiki/Abell_Catalog_of_Planetary_Nebulae" title="Abell Catalog of Planetary Nebulae">Abell Catalog of Planetary Nebulae</a></li> <li><a href="/wiki/Barnard_Catalogue" title="Barnard Catalogue">Barnard Catalogue</a> (dark nebulae)</li> <li><a href="/wiki/Lynds%27_Catalogue_of_Bright_Nebulae" title="Lynds' Catalogue of Bright Nebulae">Lynds' Catalogue of Bright Nebulae</a></li> <li><a href="/wiki/Lynds%27_Catalogue_of_Dark_Nebulae" title="Lynds' Catalogue of Dark Nebulae">Lynds' Catalogue of Dark Nebulae</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=12" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/H_I_region" title="H I region">H I region</a></li> <li><a href="/wiki/H_II_region" title="H II region">H II region</a></li> <li><a href="/wiki/List_of_largest_nebulae" title="List of largest nebulae">List of largest nebulae</a></li> <li><a href="/wiki/List_of_diffuse_nebulae" title="List of diffuse nebulae">List of diffuse nebulae</a></li> <li><a href="/wiki/Lists_of_nebulae" title="Lists of nebulae">Lists of nebulae</a></li> <li><a href="/wiki/Molecular_cloud" title="Molecular cloud">Molecular cloud</a></li> <li><a href="/wiki/Magellanic_Clouds" title="Magellanic Clouds">Magellanic Clouds</a></li> <li><a href="/wiki/Messier_object" title="Messier object">Messier object</a></li> <li><a href="/wiki/Nebular_hypothesis" title="Nebular hypothesis">Nebular hypothesis</a></li> <li><a href="/wiki/Orion_molecular_cloud_complex" title="Orion molecular cloud complex">Orion molecular cloud complex</a></li> <li><a href="/wiki/Timeline_of_knowledge_about_the_interstellar_and_intergalactic_medium" title="Timeline of knowledge about the interstellar and intergalactic medium">Timeline of knowledge about the interstellar and intergalactic medium</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=13" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <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"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><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="CITEREFHarper" class="citation web cs1">Harper, Douglas. <a rel="nofollow" class="external text" href="https://www.etymonline.com/?term=nebula">"nebula"</a>. <i><a href="/wiki/Online_Etymology_Dictionary" class="mw-redirect" title="Online Etymology Dictionary">Online Etymology Dictionary</a></i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Online+Etymology+Dictionary&rft.atitle=nebula&rft.aulast=Harper&rft.aufirst=Douglas&rft_id=https%3A%2F%2Fwww.etymonline.com%2F%3Fterm%3Dnebula&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><i>American Heritage Dictionary of the English Language, Fifth Edition</i>. S.v. "nebula." Retrieved November 23, 2019, via <a rel="nofollow" class="external free" href="https://thefreedictionary.com/nebula">https://thefreedictionary.com/nebula</a></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><i>Collins English Dictionary – Complete and Unabridged, 12th Edition 2014</i>. S.v. "nebula." Retrieved November 23, 2019, via <a rel="nofollow" class="external free" href="https://thefreedictionary.com/nebula">https://thefreedictionary.com/nebula</a></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><i>Random House Kernerman Webster's College Dictionary</i>. S.v. "nebula." Retrieved November 23, 2019, via <a rel="nofollow" class="external free" href="https://thefreedictionary.com/nebula">https://thefreedictionary.com/nebula</a></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><i>The American Heritage Dictionary of Student Science, Second Edition</i>. S.v. "nebula." Retrieved November 23, 2019, via <a rel="nofollow" class="external free" href="https://thefreedictionary.com/nebula">https://thefreedictionary.com/nebula</a></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFHowell,_Elizabeth2013" class="citation news cs1">Howell, Elizabeth (2013-02-22). <a rel="nofollow" class="external text" href="http://www.universetoday.com/99989/in-reality-nebulae-offer-no-place-for-spaceships-to-hide/">"In Reality, Nebulae Offer No Place for Spaceships to Hide"</a>. <i>Universe Today</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Universe+Today&rft.atitle=In+Reality%2C+Nebulae+Offer+No+Place+for+Spaceships+to+Hide&rft.date=2013-02-22&rft.au=Howell%2C+Elizabeth&rft_id=http%3A%2F%2Fwww.universetoday.com%2F99989%2Fin-reality-nebulae-offer-no-place-for-spaceships-to-hide%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFClark,_Roger_N.1990" class="citation book cs1">Clark, Roger N. (1990). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=gCI9AAAAIAAJ&pg=PA98"><i>Visual astronomy of the deep sky</i></a>. Cambridge University Press. p. 98. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9780521361552" title="Special:BookSources/9780521361552"><bdi>9780521361552</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Visual+astronomy+of+the+deep+sky&rft.pages=98&rft.pub=Cambridge+University+Press&rft.date=1990&rft.isbn=9780521361552&rft.au=Clark%2C+Roger+N.&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DgCI9AAAAIAAJ%26pg%3DPA98&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://spacecenter.org/what-is-a-nebula/">"What is a nebula?"</a>. <i>Space Center Houston</i>. March 19, 2020<span class="reference-accessdate">. Retrieved <span class="nowrap">June 27,</span> 2021</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Space+Center+Houston&rft.atitle=What+is+a+nebula%3F&rft.date=2020-03-19&rft_id=https%3A%2F%2Fspacecenter.org%2Fwhat-is-a-nebula%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKunitzsch1987" class="citation cs2">Kunitzsch, P. (1987), <a rel="nofollow" class="external text" href="http://www.eso.org/sci/publications/messenger/archive/no.49-sep87/messenger-no49-42-43.pdf">"A Medieval Reference to the Andromeda Nebula"</a> <span class="cs1-format">(PDF)</span>, <i><a href="/wiki/ESO_Messenger" class="mw-redirect" title="ESO Messenger">ESO Messenger</a></i>, <b>49</b>: <span class="nowrap">42–</span>43, <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/1987Msngr..49...42K">1987Msngr..49...42K</a><span class="reference-accessdate">, retrieved <span class="nowrap">2009-10-31</span></span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=ESO+Messenger&rft.atitle=A+Medieval+Reference+to+the+Andromeda+Nebula&rft.volume=49&rft.pages=%3Cspan+class%3D%22nowrap%22%3E42-%3C%2Fspan%3E43&rft.date=1987&rft_id=info%3Abibcode%2F1987Msngr..49...42K&rft.aulast=Kunitzsch&rft.aufirst=P.&rft_id=http%3A%2F%2Fwww.eso.org%2Fsci%2Fpublications%2Fmessenger%2Farchive%2Fno.49-sep87%2Fmessenger-no49-42-43.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-Jones-10"><span class="mw-cite-backlink">^ <a href="#cite_ref-Jones_10-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Jones_10-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFJones,_Kenneth_Glyn1991" class="citation book cs1">Jones, Kenneth Glyn (1991). <i>Messier's nebulae and star clusters</i>. Cambridge University Press. p. 1. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-521-37079-5" title="Special:BookSources/0-521-37079-5"><bdi>0-521-37079-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Messier%27s+nebulae+and+star+clusters&rft.pages=1&rft.pub=Cambridge+University+Press&rft.date=1991&rft.isbn=0-521-37079-5&rft.au=Jones%2C+Kenneth+Glyn&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-rasqj25-11"><span class="mw-cite-backlink">^ <a href="#cite_ref-rasqj25_11-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-rasqj25_11-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFHarrison1984" class="citation journal cs1">Harrison, T. G. (March 1984). "The Orion Nebula – where in History is it". <i><a href="/wiki/Quarterly_Journal_of_the_Royal_Astronomical_Society" class="mw-redirect" title="Quarterly Journal of the Royal Astronomical Society">Quarterly Journal of the Royal Astronomical Society</a></i>. <b>25</b> (1): <span class="nowrap">70–</span>73. <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/1984QJRAS..25...65H">1984QJRAS..25...65H</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Quarterly+Journal+of+the+Royal+Astronomical+Society&rft.atitle=The+Orion+Nebula+%E2%80%93+where+in+History+is+it&rft.volume=25&rft.issue=1&rft.pages=%3Cspan+class%3D%22nowrap%22%3E70-%3C%2Fspan%3E73&rft.date=1984-03&rft_id=info%3Abibcode%2F1984QJRAS..25...65H&rft.aulast=Harrison&rft.aufirst=T.+G.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-Lundmark-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-Lundmark_12-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFLundmark1921" class="citation journal cs1">Lundmark, K (1921). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F123101">"Suspected New Stars Recorded in the Old Chronicles and Among Recent Meridian Observations"</a>. <i>Publications of the Astronomical Society of the Pacific</i>. <b>33</b> (195): 225. <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/1921PASP...33..225L">1921PASP...33..225L</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F123101">10.1086/123101</a></span>.</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=Suspected+New+Stars+Recorded+in+the+Old+Chronicles+and+Among+Recent+Meridian+Observations&rft.volume=33&rft.issue=195&rft.pages=225&rft.date=1921&rft_id=info%3Adoi%2F10.1086%2F123101&rft_id=info%3Abibcode%2F1921PASP...33..225L&rft.aulast=Lundmark&rft.aufirst=K&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F123101&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-Mayall-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-Mayall_13-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFMayall1939" class="citation journal cs1">Mayall, N.U. (1939). <a rel="nofollow" class="external text" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1939ASPL....3..145M&link_type=ARTICLE&db_key=AST">"The Crab Nebula, a Probable Supernova"</a>. <i>Astronomical Society of the Pacific Leaflets</i>. <b>3</b> (119): 145. <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/1939ASPL....3..145M">1939ASPL....3..145M</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Astronomical+Society+of+the+Pacific+Leaflets&rft.atitle=The+Crab+Nebula%2C+a+Probable+Supernova&rft.volume=3&rft.issue=119&rft.pages=145&rft.date=1939&rft_id=info%3Abibcode%2F1939ASPL....3..145M&rft.aulast=Mayall&rft.aufirst=N.U.&rft_id=http%3A%2F%2Fadsabs.harvard.edu%2Fcgi-bin%2Fnph-data_query%3Fbibcode%3D1939ASPL....3..145M%26link_type%3DARTICLE%26db_key%3DAST&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFHalley1714–1716" class="citation journal cs1">Halley, E. (1714–1716). "An account of several nebulae or lucid spots like clouds, lately discovered among the fixed stars by help of the telescope". <i><a href="/wiki/Philosophical_Transactions" class="mw-redirect" title="Philosophical Transactions">Philosophical Transactions</a></i>. <b>XXXIX</b>: <span class="nowrap">390–</span>92.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Philosophical+Transactions&rft.atitle=An+account+of+several+nebulae+or+lucid+spots+like+clouds%2C+lately+discovered+among+the+fixed+stars+by+help+of+the+telescope&rft.volume=XXXIX&rft.pages=%3Cspan+class%3D%22nowrap%22%3E390-%3C%2Fspan%3E92&rft.date=1714%2F1716&rft.aulast=Halley&rft.aufirst=E.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span> </span> </li> <li id="cite_note-hoskin2005-15"><span class="mw-cite-backlink">^ <a href="#cite_ref-hoskin2005_15-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-hoskin2005_15-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFHoskin2005" class="citation journal cs1">Hoskin, Michael (2005). "Unfinished Business: William Herschel's Sweeps for Nebulae". <i><a href="/wiki/British_Journal_for_the_History_of_Science" class="mw-redirect" title="British Journal for the History of Science">British Journal for the History of Science</a></i>. <b>43</b> (3): <span class="nowrap">305–</span>320. <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/2005HisSc..43..305H">2005HisSc..43..305H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1177%2F007327530504300303">10.1177/007327530504300303</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:161558679">161558679</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=British+Journal+for+the+History+of+Science&rft.atitle=Unfinished+Business%3A+William+Herschel%27s+Sweeps+for+Nebulae&rft.volume=43&rft.issue=3&rft.pages=%3Cspan+class%3D%22nowrap%22%3E305-%3C%2Fspan%3E320&rft.date=2005&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A161558679%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1177%2F007327530504300303&rft_id=info%3Abibcode%2F2005HisSc..43..305H&rft.aulast=Hoskin&rft.aufirst=Michael&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://archive.org/details/philosophicaltr04unkngoog"><i>Philosophical Transactions</i></a>. T.N. 1786. p. <a rel="nofollow" class="external text" href="https://archive.org/details/philosophicaltr04unkngoog/page/n479">457</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Philosophical+Transactions&rft.pages=457&rft.pub=T.N.&rft.date=1786&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fphilosophicaltr04unkngoog&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFWatts,_William_MarshallHuggins,_Sir_WilliamLady_Huggins1904" class="citation book cs1">Watts, William Marshall; Huggins, Sir William; Lady Huggins (1904). <a rel="nofollow" class="external text" href="https://archive.org/details/anintroductiont00hugggoog"><i>An introduction to the study of spectrum analysis</i></a>. Longmans, Green, and Co. pp. <a rel="nofollow" class="external text" href="https://archive.org/details/anintroductiont00hugggoog/page/n106">84</a>–85<span class="reference-accessdate">. Retrieved <span class="nowrap">2009-10-31</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=An+introduction+to+the+study+of+spectrum+analysis&rft.pages=84-85&rft.pub=Longmans%2C+Green%2C+and+Co.&rft.date=1904&rft.au=Watts%2C+William+Marshall&rft.au=Huggins%2C+Sir+William&rft.au=Lady+Huggins&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fanintroductiont00hugggoog&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-struve37-18"><span class="mw-cite-backlink">^ <a href="#cite_ref-struve37_18-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-struve37_18-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-struve37_18-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFStruve1937" class="citation journal cs1">Struve, Otto (1937). "Recent Progress in the Study of Reflection Nebulae". <i>Popular Astronomy</i>. <b>45</b>: <span class="nowrap">9–</span>22. <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/1937PA.....45....9S">1937PA.....45....9S</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Popular+Astronomy&rft.atitle=Recent+Progress+in+the+Study+of+Reflection+Nebulae&rft.volume=45&rft.pages=%3Cspan+class%3D%22nowrap%22%3E9-%3C%2Fspan%3E22&rft.date=1937&rft_id=info%3Abibcode%2F1937PA.....45....9S&rft.aulast=Struve&rft.aufirst=Otto&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFSlipher1912" class="citation journal cs1">Slipher, V. M. (1912). "On the spectrum of the nebula in the Pleiades". <i>Lowell Observatory Bulletin</i>. <b>1</b>: <span class="nowrap">26–</span>27. <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/1912LowOB...2...26S">1912LowOB...2...26S</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Lowell+Observatory+Bulletin&rft.atitle=On+the+spectrum+of+the+nebula+in+the+Pleiades&rft.volume=1&rft.pages=%3Cspan+class%3D%22nowrap%22%3E26-%3C%2Fspan%3E27&rft.date=1912&rft_id=info%3Abibcode%2F1912LowOB...2...26S&rft.aulast=Slipher&rft.aufirst=V.+M.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFHubble1922" class="citation journal cs1">Hubble, E. P. (December 1922). <a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F142713">"The source of luminosity in galactic nebulae"</a>. <i>Astrophysical Journal</i>. <b>56</b>: <span class="nowrap">400–</span>438. <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/1922ApJ....56..400H">1922ApJ....56..400H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1086%2F142713">10.1086/142713</a></span>.</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+source+of+luminosity+in+galactic+nebulae.&rft.volume=56&rft.pages=%3Cspan+class%3D%22nowrap%22%3E400-%3C%2Fspan%3E438&rft.date=1922-12&rft_id=info%3Adoi%2F10.1086%2F142713&rft_id=info%3Abibcode%2F1922ApJ....56..400H&rft.aulast=Hubble&rft.aufirst=E.+P.&rft_id=https%3A%2F%2Fdoi.org%2F10.1086%252F142713&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation news cs1"><a rel="nofollow" class="external text" href="http://www.spacetelescope.org/images/potw1350a/">"A stellar sneezing fit"</a>. <i>ESA/Hubble Picture of the Week</i><span class="reference-accessdate">. Retrieved <span class="nowrap">16 December</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=ESA%2FHubble+Picture+of+the+Week&rft.atitle=A+stellar+sneezing+fit&rft_id=http%3A%2F%2Fwww.spacetelescope.org%2Fimages%2Fpotw1350a%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-Integrated_Flux_Nebula_:0-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-Integrated_Flux_Nebula_:0_22-0">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external free" href="http://www.aicccd.com/archive/aic2005/The_unexplored_nebula_project-smandel.pdf">http://www.aicccd.com/archive/aic2005/The_unexplored_nebula_project-smandel.pdf</a> </span> </li> <li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFChadwickCooper2012" class="citation book cs1">Chadwick, Stephen; Cooper, Ian (11 December 2012). <i>Imaging the Southern Sky</i>. Springer. p. 248. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1461447498" title="Special:BookSources/978-1461447498"><bdi>978-1461447498</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Imaging+the+Southern+Sky&rft.pages=248&rft.pub=Springer&rft.date=2012-12-11&rft.isbn=978-1461447498&rft.aulast=Chadwick&rft.aufirst=Stephen&rft.au=Cooper%2C+Ian&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-Messier-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-Messier_24-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/19961225125109/http://messier.seds.org/diffuse.html">"The Messier Catalog: Diffuse Nebulae"</a>. SEDS. Archived from <a rel="nofollow" class="external text" href="http://messier.seds.org/diffuse.html">the original</a> on 1996-12-25<span class="reference-accessdate">. Retrieved <span class="nowrap">2007-06-12</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+Messier+Catalog%3A+Diffuse+Nebulae&rft.pub=SEDS&rft_id=http%3A%2F%2Fmessier.seds.org%2Fdiffuse.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-shu1982-25"><span class="mw-cite-backlink">^ <a href="#cite_ref-shu1982_25-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-shu1982_25-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-shu1982_25-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-shu1982_25-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-shu1982_25-4"><sup><i><b>e</b></i></sup></a> <a href="#cite_ref-shu1982_25-5"><sup><i><b>f</b></i></sup></a> <a href="#cite_ref-shu1982_25-6"><sup><i><b>g</b></i></sup></a> <a href="#cite_ref-shu1982_25-7"><sup><i><b>h</b></i></sup></a> <a href="#cite_ref-shu1982_25-8"><sup><i><b>i</b></i></sup></a> <a href="#cite_ref-shu1982_25-9"><sup><i><b>j</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFF._H._Shu1982" class="citation book cs1">F. H. Shu (1982). <span class="id-lock-registration" title="Free registration required"><a rel="nofollow" class="external text" href="https://archive.org/details/physicaluniverse00shuf"><i>The Physical Universe</i></a></span>. Mill Valley, California: University Science Books. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-935702-05-9" title="Special:BookSources/0-935702-05-9"><bdi>0-935702-05-9</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+Physical+Universe&rft.place=Mill+Valley%2C+California&rft.pub=University+Science+Books&rft.date=1982&rft.isbn=0-935702-05-9&rft.au=F.+H.+Shu&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fphysicaluniverse00shuf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-s-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-s_26-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFChaisson,_E.McMillan,_S.1995" class="citation book cs1">Chaisson, E.; McMillan, S. (1995). <i>Astronomy: a beginner's guide to the universe</i> (2nd ed.). Upper Saddle River, New Jersey: Prentice-Hall. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-13-733916-X" title="Special:BookSources/0-13-733916-X"><bdi>0-13-733916-X</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Astronomy%3A+a+beginner%27s+guide+to+the+universe&rft.place=Upper+Saddle+River%2C+New+Jersey&rft.edition=2nd&rft.pub=Prentice-Hall&rft.date=1995&rft.isbn=0-13-733916-X&rft.au=Chaisson%2C+E.&rft.au=McMillan%2C+S.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-Protoplanetary_nebula_Sahai_&_Sanchez_Contreras_et_al_2005-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-Protoplanetary_nebula_Sahai_&_Sanchez_Contreras_et_al_2005_27-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFSahaiSánchez_ContrerasMorris2005" class="citation journal cs1">Sahai, Raghvendra; Sánchez Contreras, Carmen; Morris, Mark (2005). <a rel="nofollow" class="external text" href="https://trs.jpl.nasa.gov/bitstream/2014/40924/1/04-3294.pdf">"A Starfish Preplanetary Nebula: IRAS 19024+0044"</a> <span class="cs1-format">(PDF)</span>. <i>The Astrophysical Journal</i>. <b>620</b> (2): <span class="nowrap">948–</span>960. <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...620..948S">2005ApJ...620..948S</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%2F426469">10.1086/426469</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=A+Starfish+Preplanetary+Nebula%3A+IRAS+19024%2B0044&rft.volume=620&rft.issue=2&rft.pages=%3Cspan+class%3D%22nowrap%22%3E948-%3C%2Fspan%3E960&rft.date=2005&rft_id=info%3Adoi%2F10.1086%2F426469&rft_id=info%3Abibcode%2F2005ApJ...620..948S&rft.aulast=Sahai&rft.aufirst=Raghvendra&rft.au=S%C3%A1nchez+Contreras%2C+Carmen&rft.au=Morris%2C+Mark&rft_id=https%3A%2F%2Ftrs.jpl.nasa.gov%2Fbitstream%2F2014%2F40924%2F1%2F04-3294.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> <li id="cite_note-Protoplanetary_nebula_Kastner2005-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-Protoplanetary_nebula_Kastner2005_28-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222" /><cite id="CITEREFKastner2005" class="citation cs2">Kastner, J. H. (2005), "Near-death Transformation: Mass Ejection in Planetary Nebulae and Protoplanetary Nebulae", <i>American Astronomical Society Meeting 206, #28.04; Bulletin of the American Astronomical Society</i>, <b>37</b>, <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/2005AAS...206.2804K">2005AAS...206.2804K</a></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=American+Astronomical+Society+Meeting+206%2C+%2328.04%3B+Bulletin+of+the+American+Astronomical+Society&rft.atitle=Near-death+Transformation%3A+Mass+Ejection+in+Planetary+Nebulae+and+Protoplanetary+Nebulae&rft.volume=37&rft.date=2005&rft_id=info%3Abibcode%2F2005AAS...206.2804K&rft.aulast=Kastner&rft.aufirst=J.+H.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ANebula" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Nebula&action=edit&section=14" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://messier.seds.org/nebula.html">Nebulae</a>, SEDS Messier Pages</li> <li><a rel="nofollow" class="external text" href="http://fusedweb.pppl.gov">Fusedweb.pppl.gov</a></li> <li><a rel="nofollow" class="external text" href="https://bibnum.obspm.fr/solr-search?q=n%C3%A9buleuse">Historical pictures of nebulae</a>, digital library of Paris Observatory</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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.navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Nebulae" title="Template:Nebulae"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Nebulae" title="Template talk:Nebulae"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Nebulae" title="Special:EditPage/Template:Nebulae"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Nebulae699" style="font-size:114%;margin:0 4em"><a class="mw-selflink selflink">Nebulae</a></div></th></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%">Visible nebula</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Dark_nebula" title="Dark nebula">Dark nebula</a></li> <li><a href="/wiki/Diffuse_nebula" class="mw-redirect" title="Diffuse nebula">Diffuse nebula</a> <ul><li><a href="/wiki/Emission_nebula" title="Emission nebula">Emission nebula</a> <ul><li><a href="/wiki/Planetary_nebula" title="Planetary nebula">Planetary nebula</a></li> <li><a href="/wiki/Supernova_remnant" title="Supernova remnant">Supernova remnant</a></li> <li><a href="/wiki/Nova_remnant" title="Nova remnant">Nova remnant</a></li> <li><a href="/wiki/H_II_region" title="H II region">H II region</a></li></ul></li> <li><a href="/wiki/Reflection_nebula" title="Reflection nebula">Reflection nebula</a> <ul><li><a href="/wiki/Variable_nebula" title="Variable nebula">Variable nebula</a></li> <li><a href="/wiki/Protoplanetary_nebula" title="Protoplanetary nebula">Protoplanetary nebula</a></li></ul></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%"><a href="/wiki/Category:Pre-stellar_nebulae" title="Category:Pre-stellar nebulae">Pre-stellar nebulae</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Giant_molecular_cloud" class="mw-redirect" title="Giant molecular cloud">Giant molecular cloud</a></li> <li><a href="/wiki/Bok_globule" title="Bok globule">Bok globule</a></li> <li><a href="/wiki/Evaporating_gaseous_globule" title="Evaporating gaseous globule">Evaporating gaseous globule</a></li> <li><a href="/wiki/Solar_nebula" class="mw-redirect" title="Solar nebula">Solar nebula</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%">Stellar nebula</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Nova_remnant" title="Nova remnant">Nova remnant</a></li> <li><a href="/wiki/Protoplanetary_nebula" title="Protoplanetary nebula">Protoplanetary nebula</a></li> <li><a href="/wiki/Wolf%E2%80%93Rayet_nebula" title="Wolf–Rayet nebula">Wolf–Rayet nebula</a></li> <li><a href="/wiki/Integrated_Flux_Nebula" title="Integrated Flux Nebula">Integrated Flux Nebula</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%"><a href="/wiki/Category:Post-stellar_nebulae" title="Category:Post-stellar nebulae">Post-stellar nebulae</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Planetary_nebula" title="Planetary nebula">Planetary nebula</a></li> <li><a href="/wiki/Supernova_remnant" title="Supernova remnant">Supernova remnant</a></li> <li><a href="/wiki/Pulsar_wind_nebula" title="Pulsar wind nebula">Pulsar wind nebula</a></li> <li><a href="/wiki/Superbubble" title="Superbubble">Supershell</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%">Clouds</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Interstellar_cloud" title="Interstellar cloud">Interstellar cloud</a> <ul><li><a href="/wiki/Molecular_cloud" title="Molecular cloud">Molecular cloud</a></li> <li><a href="/wiki/Infrared_cirrus" title="Infrared cirrus">Infrared cirrus</a></li></ul></li> <li><a href="/wiki/High-velocity_cloud" title="High-velocity cloud">High-velocity cloud</a></li> <li><a href="/wiki/H_I_region" title="H I region">H I region</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%">Morphology</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Bipolar_nebula" title="Bipolar nebula">Bipolar nebula</a></li> <li><a href="/wiki/Pinwheel_nebula" title="Pinwheel nebula">Pinwheel nebula</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%">Intergalactic blobs</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Lyman-alpha_blob" title="Lyman-alpha blob">Lyman-alpha blob</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%"><span class="noviewer" typeof="mw:File"><span title="List-Class article"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/16px-Symbol_list_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/23px-Symbol_list_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/d/db/Symbol_list_class.svg/31px-Symbol_list_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Lists_of_nebulae" title="Lists of nebulae">Lists</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_diffuse_nebulae" title="List of diffuse nebulae">Diffuse</a></li> <li><a href="/wiki/List_of_largest_nebulae" title="List of largest nebulae">Largest Nebulae</a></li> <li><a href="/wiki/List_of_planetary_nebulae" title="List of planetary nebulae">Planetary</a> (PNe)</li> <li><a href="/wiki/List_of_protoplanetary_nebulae" title="List of protoplanetary nebulae">Protoplanetary</a> (PPNe)</li> <li><a href="/wiki/List_of_supernova_remnants" title="List of supernova remnants">Supernova remnants</a> (SNRs)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="text-align:center;;width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cometary_knot" title="Cometary knot">Cometary knot</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2" style="text-align:center;"><div><div class="hlist"> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Nebulae" title="Category:Nebulae">Category</a></li> <li><span class="noviewer" typeof="mw:File"><span title="Commons page"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/20px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" 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