The Danish 1.54-metre Hβ Photometer

<!DOCTYPE html> <html lang="en"> <head prefix="og: http://ogp.me/ns# fb: http://ogp.me/ns/fb#"> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <base target="_top" /> <meta name="robots" content="index,follow" /> <meta name="author" content="information@eso.org" /> <meta name="description" content="ESO, European Organisation for Astronomical Research in the Southern Hemisphere" /> <meta name="keywords" content="ESO, eso.org, Astronomy, Astrophysics, Astronomie, Suedsternwarte, telescopes, detectors, comets, planets, stars, galaxies, nebulae, universe, NTT, VLT, VLTI, ALMA, ELT, La Silla, Paranal, Garching, Chile" /> <meta name="statvooVerification" content="f546f5bccd3fb7f8c5d8e97c6beab814" /> <link rel="alternate" href="https://www.eso.org/public/teles-instr/lasilla/danish154/hb-photometer/" hreflang="x-default" /><link rel="alternate" href="https://www.eso.org/public/australia/teles-instr/lasilla/danish154/hb-photometer/" hreflang="en-au" /><link rel="alternate" href="https://www.eso.org/public/unitedkingdom/teles-instr/lasilla/danish154/hb-photometer/" hreflang="en-gb" /><link rel="alternate" href="https://www.eso.org/public/ireland/teles-instr/lasilla/danish154/hb-photometer/" hreflang="en-ie" /><link rel="alternate" href="https://www.eso.org/public/czechrepublic/teles-instr/lasilla/danish154/hb-photometer/" hreflang="cs" /><link rel="alternate" href="https://www.eso.org/public/denmark/teles-instr/lasilla/danish154/hb-photometer/" hreflang="da" /><link rel="alternate" href="https://www.eso.org/public/netherlands/teles-instr/lasilla/danish154/hb-photometer/" hreflang="nl" /><link rel="alternate" href="https://www.eso.org/public/belgium-nl/teles-instr/lasilla/danish154/hb-photometer/" hreflang="nl-be" /><link rel="alternate" href="https://www.eso.org/public/finland/teles-instr/lasilla/danish154/hb-photometer/" hreflang="fi" /><link rel="alternate" href="https://www.eso.org/public/france/teles-instr/lasilla/danish154/hb-photometer/" hreflang="fr" /><link rel="alternate" href="https://www.eso.org/public/belgium-fr/teles-instr/lasilla/danish154/hb-photometer/" hreflang="fr-be" /><link rel="alternate" href="https://www.eso.org/public/switzerland-fr/teles-instr/lasilla/danish154/hb-photometer/" hreflang="fr-ch" /><link rel="alternate" href="https://www.eso.org/public/germany/teles-instr/lasilla/danish154/hb-photometer/" hreflang="de" /><link rel="alternate" href="https://www.eso.org/public/austria/teles-instr/lasilla/danish154/hb-photometer/" hreflang="de-at" /><link rel="alternate" href="https://www.eso.org/public/belgium-de/teles-instr/lasilla/danish154/hb-photometer/" hreflang="de-be" /><link rel="alternate" href="https://www.eso.org/public/switzerland-de/teles-instr/lasilla/danish154/hb-photometer/" hreflang="de-ch" /><link rel="alternate" href="https://www.eso.org/public/italy/teles-instr/lasilla/danish154/hb-photometer/" hreflang="it" /><link rel="alternate" href="https://www.eso.org/public/switzerland-it/teles-instr/lasilla/danish154/hb-photometer/" hreflang="it-ch" /><link rel="alternate" href="https://www.eso.org/public/poland/teles-instr/lasilla/danish154/hb-photometer/" hreflang="pl" /><link rel="alternate" href="https://www.eso.org/public/portugal/teles-instr/lasilla/danish154/hb-photometer/" hreflang="pt" /><link rel="alternate" href="https://www.eso.org/public/spain/teles-instr/lasilla/danish154/hb-photometer/" hreflang="es" /><link rel="alternate" href="https://www.eso.org/public/chile/teles-instr/lasilla/danish154/hb-photometer/" hreflang="es-cl" /><link rel="alternate" href="https://www.eso.org/public/sweden/teles-instr/lasilla/danish154/hb-photometer/" hreflang="sv" /> <link rel="shortcut icon" href="https://www.eso.org/public/archives/favicon.ico" /> <title>The Danish 1.54-metre Hβ Photometer | ESO</title>  <style type="text/css"> @import url("https://fast.fonts.net/t/1.css?apiType=css&projectid=03892b9b-79f6-4f01-9746-af912ebf5e47"); </style> <link href="/public/archives/djp/css/main.9116bda0b9f3.css" rel="stylesheet" type="text/css" /> <link href="https://feeds.feedburner.com/EsoTopNews" rel="alternate" type="application/rss+xml" title="ESO Top News" /> <link href="https://feeds.feedburner.com/EsoAnnouncements" rel="alternate" type="application/rss+xml" title="ESO Announcements" /> <link href="https://feeds.feedburner.com/ESOcast" rel="alternate" type="application/rss+xml" title="ESOCast" /> <link href="https://recruitment.eso.org/jobs.rss" rel="alternate" type="application/rss+xml" title="Jobs@ESO" /> <link href="https://www.eso.org/public/blog/feed/" rel="alternate" type="application/rss+xml" title="ESOblog" />  <meta name="twitter:card" content="summary" /> <meta name="twitter:site" content="@ESO" /> <meta name="twitter:creator" content="@ESO" />  <script type="text/javascript"> var _paq = window._paq || []; /* tracker methods like "setCustomDimension" should be called before "trackPageView" */ _paq.push(['trackPageView']); _paq.push(['enableLinkTracking']); (function() { var u="/mtmo/"; _paq.push(['setTrackerUrl', u+'matomo.php']); _paq.push(['setSiteId', '1']); var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; g.type='text/javascript'; g.async=true; g.defer=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s); })(); </script>  <meta property="og:title" content="The Danish 1.54-metre Hβ Photometer" /> </head> <body> <input type='hidden' name='csrfmiddlewaretoken' value='nAw2NqGcNPxDW0jFvwvpP8pVSa4TjHNA4QvzjGvcr5wviivwNpnD2F7YwXySAwnj' /> <div id="privacy-notice" style="display: none"> <p> By continuing to use this website, you are giving consent to our use of cookies.<br> For more information on how ESO uses data and how you can disable cookies, please view <a href="/public/about-eso/privacy/"> our privacy policy</a>. </p> <button type="button" class="btn btn-primary" onclick="accept_privacy_notice()"> Accept </button> <script> // Display the privacy cookie if the cookie is not set if (!has_privacy_cookie()) { document.getElementById('privacy-notice').style.display = 'block' } function has_privacy_cookie() { return document.cookie.split(';').filter(function(item) { return item.indexOf('privacy_notice_accepted=True') >= 0 }).length > 0 } function accept_privacy_notice() { let data = { LANGUAGE_CODE: 'en' } let csrftoken = getCookie('csrftoken'); let headers = new Headers(); headers.append('Content-Type', 'application/json; charset=utf-8'); headers.append('X-CSRFToken', csrftoken); fetch('/public/accept-privacy-notice/', { method: 'post', headers: headers, credentials: 'include', body: JSON.stringify(data) }).then( document.getElementById('privacy-notice').style.display = 'none' ) } function getCookie(name) { var cookieValue = null; if (document.cookie && document.cookie !== '') { var cookies = document.cookie.split(';'); for (var i = 0; i < cookies.length; i++) { var cookie = jQuery.trim(cookies[i]); // Does this cookie string begin with the name we want? if (cookie.substring(0, name.length + 1) == (name + '=')) { cookieValue = decodeURIComponent(cookie.substring(name.length + 1)); break; } } } return cookieValue; } </script> </div> <nav class="navbar-general-wrapper" role="navigation"> <div class="navbar-general"> <div class="minilogo"> <a href="/public/"> <div class="sprites-esologo-23-30" title="European Organisation for Astronomical Research in the Southern Hemisphere"></div> </a> </div> <div id="select-language"> <div class="flags"> <div title="Austria" class="sprites-flag_at"></div> <div title="Belgium" class="sprites-flag_be"></div> <div title="Czechia" class="sprites-flag_cz"></div> <div title="Denmark" class="sprites-flag_da"></div> <div title="Finland" class="sprites-flag_fi"></div> <div title="France" class="sprites-flag_fr"></div> <div title="Germany" class="sprites-flag_de"></div> <div title="Ireland" class="sprites-flag_ie"></div> <div title="Italy" class="sprites-flag_it"></div> <div title="Netherlands" class="sprites-flag_nl"></div> <div title="Poland" class="sprites-flag_pl"></div> <div title="Portugal" class="sprites-flag_pt"></div> <div title="Spain" class="sprites-flag_es"></div> <div title="Sweden" class="sprites-flag_sv"></div> <div title="Switzerland" class="sprites-flag_ch"></div> <div title="UK" class="sprites-flag_gb"></div> <div style="margin-left: 8px" title="Chile" class="sprites-flag_cl"></div> </div> <div class="languages"> <div class="language-button"> <span class="language-text">Select Language (en)</span> <div class="language-flag"><div title="en" class="flag sprites-flag_gb"> </div><span> (en)</span></div> <span class="caret"></span> </div> <ul class="languages-dropdown" role="menu"> <li class="language selected"><a role="menuitem" href="/public/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="International English" class="flag sprites-flag_en"> </div>International English</a></li> <li class="language"><a role="menuitem" href="/public/denmark/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Dansk" class="flag sprites-flag_da"> </div>Dansk</a></li> <li class="language"><a role="menuitem" href="/public/germany/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Deutsch" class="flag sprites-flag_de"> </div>Deutsch</a></li> <li class="language"><a role="menuitem" href="/public/belgium-de/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Deutsch (Belgien)" class="flag sprites-flag_be"> </div>Deutsch (Belgien)</a></li> <li class="language"><a role="menuitem" href="/public/switzerland-de/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Deutsch (Schweiz)" class="flag sprites-flag_ch"> </div>Deutsch (Schweiz)</a></li> <li class="language"><a role="menuitem" href="/public/austria/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Deutsch (Österreich)" class="flag sprites-flag_at"> </div>Deutsch (Österreich)</a></li> <li class="language"><a role="menuitem" href="/public/australia/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="English (Australia)" class="flag sprites-flag_au"> </div>English (Australia)</a></li> <li class="language"><a role="menuitem" href="/public/ireland/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="English (Ireland)" class="flag sprites-flag_ie"> </div>English (Ireland)</a></li> <li class="language"><a role="menuitem" href="/public/unitedkingdom/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="English (UK)" class="flag sprites-flag_gb"> </div>English (UK)</a></li> <li class="language"><a role="menuitem" href="/public/spain/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Español" class="flag sprites-flag_es"> </div>Español</a></li> <li class="language"><a role="menuitem" href="/public/chile/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Español (Chile)" class="flag sprites-flag_cl"> </div>Español (Chile)</a></li> <li class="language"><a role="menuitem" href="/public/france/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Français" class="flag sprites-flag_fr"> </div>Français</a></li> <li class="language"><a role="menuitem" href="/public/belgium-fr/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Français (Belgique)" class="flag sprites-flag_be"> </div>Français (Belgique)</a></li> <li class="language"><a role="menuitem" href="/public/switzerland-fr/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Français (Suisse)" class="flag sprites-flag_ch"> </div>Français (Suisse)</a></li> <li class="language"><a role="menuitem" href="/public/italy/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Italiano" class="flag sprites-flag_it"> </div>Italiano</a></li> <li class="language"><a role="menuitem" href="/public/switzerland-it/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Italiano (Svizzera)" class="flag sprites-flag_ch"> </div>Italiano (Svizzera)</a></li> <li class="language"><a role="menuitem" href="/public/netherlands/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Nederlands" class="flag sprites-flag_nl"> </div>Nederlands</a></li> <li class="language"><a role="menuitem" href="/public/belgium-nl/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Nederlands (België)" class="flag sprites-flag_be"> </div>Nederlands (België)</a></li> <li class="language"><a role="menuitem" href="/public/poland/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Polski" class="flag sprites-flag_pl"> </div>Polski</a></li> <li class="language"><a role="menuitem" href="/public/portugal/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Português" class="flag sprites-flag_pt"> </div>Português</a></li> <li class="language"><a role="menuitem" href="/public/finland/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Suomi" class="flag sprites-flag_fi"> </div>Suomi</a></li> <li class="language"><a role="menuitem" href="/public/sweden/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Svenska" class="flag sprites-flag_sv"> </div>Svenska</a></li> <li class="language"><a role="menuitem" href="/public/czechrepublic/teles-instr/lasilla/danish154/hb-photometer/?lang"><div title="Česky" class="flag sprites-flag_cs"> </div>Česky</a></li> </ul> </div> </div> <div class="sections"> <a href="https://www.eso.org/sci.html">Science</a> <a href="/UserPortal/">User Portal</a> </div> <div class="searchbox"> <button type="button" class="btn btn-default" id="searchbox-button"> <span class="fa fa-search"></span> </button> <div id="searchbox-dropdown"> <form action="/public/search/" method="get" class="form-inline" role="search"> <div class="form-group"> <div class="input-group"> <input type="text" value="" placeholder="Search..." name="q" class="form-control"> <span class="input-group-btn"> <button class="btn btn-default" type="submit"><span class="fa fa-search"></span></button> </span> </div>   </div> </form> </div> </div> <div class="links"> <a href="/public/outreach/newsletters/esonews/">Subscribe</a> <a href="/public/about-eso/travel/">Contact</a> <a href="/public/sitemap/">Site Map</a> </div> </div> </nav> <nav class="main-menu-wrapper" role="navigation"> <div class="main-menu"> <div class="mobile-menu clearfix"> <button class="menu-trigger"><span class="fa fa-navicon"></span> Open Menu</button> </div> <ul class="level0 mainmenu-aim"> <li><a href="/public/about-eso/">About<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-2" class="submenu-aim"> <li class=""><a href="/public/about-eso/esoglance/"> ESO, the European Southern Observatory </a></li><li class=""><a href="/public/about-eso/organisation/"> Organisation </a></li><li class=""><a href="/public/about-eso/mission-vision-values-strategy/"> Mission-Vision-Values-Strategy </a></li><li class="submenu"><a href="/public/about-eso/dg-office/"> Director General <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-6" class="submenu-aim sublevel"><li class="submenu"><a href="/public/about-eso/dg-office/previous-dg/"> List of Directors General <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-7" class="submenu-aim sublevel"><li class=""><a href="/public/about-eso/dg-office/xbarcons/"> Prof. Xavier Barcons </a></li><li class=""><a href="/public/about-eso/dg-office/tdezeeuw/"> Prof. T. de Zeeuw </a></li><li class=""><a href="/public/about-eso/dg-office/ccesarsk/"> Dr. C. Cesarsky </a></li><li class=""><a href="/public/about-eso/dg-office/rgiacconi/"> Prof. R. Giacconi </a></li><li class=""><a href="/public/about-eso/dg-office/hvanderlaan/"> Prof. H. van der Laan </a></li><li class=""><a href="/public/about-eso/dg-office/lwoltjer/"> Prof. L. Woltjer </a></li><li class=""><a href="/public/about-eso/dg-office/ablaauw/"> Prof. A. Blaauw </a></li><li class=""><a href="/public/about-eso/dg-office/otto-heckmann/"> Prof. O. Heckmann </a></li></ul></li></ul></li><li class=""><a href="/public/about-eso/committees.html"> ESO's Governing Bodies </a></li><li class="submenu"><a href="/public/about-eso/memberstates/"> Member States and Partners <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-17" class="submenu-aim sublevel"><li class=""><a href="/public/about-eso/memberstates/austrianinvolvement/"> Austria </a></li><li class=""><a href="/public/about-eso/memberstates/belgianinvolvement/"> Belgium </a></li><li class=""><a href="/public/about-eso/memberstates/czechinvolvement/"> Czechia </a></li><li class=""><a href="/public/about-eso/memberstates/danishinvolvement/"> Denmark </a></li><li class=""><a href="/public/about-eso/memberstates/finnishinvolvement/"> Finland </a></li><li class=""><a href="/public/about-eso/memberstates/frenchinvolvement/"> France </a></li><li class=""><a href="/public/about-eso/memberstates/germaninvolvement/"> Germany </a></li><li class=""><a href="/public/about-eso/memberstates/irishinvolvement/"> Ireland </a></li><li class=""><a href="/public/about-eso/memberstates/italianinvolvement/"> Italy </a></li><li class=""><a href="/public/about-eso/memberstates/dutchinvolvement/"> Netherlands </a></li><li class=""><a href="/public/about-eso/memberstates/polishinvolvement/"> Poland </a></li><li class=""><a href="/public/about-eso/memberstates/portugueseinvolvement/"> Portugal </a></li><li class=""><a href="/public/about-eso/memberstates/spanishinvolvement/"> Spain </a></li><li class=""><a href="/public/about-eso/memberstates/swedishinvolvement/"> Sweden </a></li><li class=""><a href="/public/about-eso/memberstates/swissinvolvement/"> Switzerland </a></li><li class=""><a href="/public/about-eso/memberstates/britishinvolvement/"> United Kingdom </a></li><li class=""><a href="/public/about-eso/strategicpartners/australianinvolvement/"> Australia (Partner) </a></li></ul></li><li class="submenu"><a href="/public/about-eso/eso-and-chile/"> ESO & Chile <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-35" class="submenu-aim sublevel"><li class=""><a href="/public/about-eso/eso-and-chile/representation-office-chile/"> ESO Representation Office in Chile </a></li></ul></li><li class="submenu"><a href="/public/about-eso/travel/"> Travel and Contacts <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-37" class="submenu-aim sublevel"><li class=""><a href="/public/about-eso/travel/garching/"> Travel to ESO Headquarters </a></li><li class=""><a href="/public/about-eso/travel/vitacura/"> Travel to Vitacura Office </a></li><li class=""><a href="/public/about-eso/travel/guesthouse/"> Travel to Guesthouse </a></li><li class=""><a href="/public/about-eso/travel/lasilla/"> Travel to La Silla </a></li><li class=""><a href="/public/about-eso/travel/laserena/"> Travel to La Serena </a></li><li class=""><a href="/public/about-eso/travel/paranal/"> Travel to Paranal </a></li><li class=""><a href="/public/about-eso/travel/antofagasta/"> Travel to Antofagasta </a></li><li class=""><a href="/public/about-eso/travel/chajnantor/"> Travel to Chajnantor </a></li><li class=""><a href="/public/about-eso/travel/elt/"> Travel to ELT Armazones </a></li></ul></li><li class="submenu"><a href="/public/about-eso/visitors/"> Visits to ESO Sites <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-47" class="submenu-aim sublevel"><li class=""><a href="/public/about-eso/visitors/paranal/"> Weekend visits to Paranal </a></li><li class=""><a href="/public/about-eso/visitors/lasilla/"> Weekend Visits to La Silla </a></li><li class=""><a href="/public/outreach/pressmedia/mediavisits/"> Media Visits </a></li><li class=""><a href="/public/about-eso/visitors/virtual-tours/"> Virtual Visits </a></li><li class=""><a href="/public/about-eso/visitors/artists-at-eso/"> Artistic Visits </a></li></ul></li><li class=""><a href="/public/about-eso/societal-benefits/"> ESO and Society </a></li><li class=""><a href="/public/about-eso/architecture/"> Architecture at ESO </a></li><li class=""><a href="/public/about-eso/collaborations/"> Collaborations with ESO </a></li><li class=""><a href="/public/about-eso/acronyms/"> ESO Acronyms </a></li><li class=""><a href="/public/about-eso/timeline/"> Timeline </a></li><li class="submenu"><a class="no-link children" href="#"> Sustainability <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-58" class="submenu-aim sublevel"><li class=""><a href="/public/about-eso/sustainability/green/"> Environmental sustainability at ESO </a></li><li class=""><a href="/public/about-eso/sustainability/eso-un-sdgs/"> ESO and the UN's Sustainable Development Goals </a></li><li class=""><a href="/public/about-eso/sustainability/dei-at-eso/"> Diversity, Equity and Inclusion </a></li></ul></li><li class="submenu"><a href="/public/about-eso/faq/"> Frequently Asked Questions <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-62" class="submenu-aim sublevel"><li class=""><a href="/public/about-eso/faq/faq-eso/"> ESO </a></li><li class=""><a href="/public/about-eso/faq/faq-vlt-paranal/"> VLT/Paranal </a></li><li class=""><a href="/public/about-eso/faq/faq-apex-alma/"> APEX/ALMA </a></li><li class=""><a href="https://elt.eso.org/about/faq/"> ELT </a></li><li class=""><a href="/public/about-eso/faq/privileges_and_immunities/"> Privileges and Immunities </a></li><li class=""><a href="/public/about-eso/faq/faq-eso-australia/"> ESO & Australia </a></li></ul></li><li class=""><a href="/public/about-eso/dark-skies-preservation/"> Dark skies preservation </a></li><li class=""><a href="/public/about-eso/privacy/"> Terms and Conditions </a></li> </ul> </div> </div> </li> <li><a href="/public/images/">Images<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-71" class="submenu-aim"> <li class=""><a href="/public/images/search/"> Advanced Search </a></li><li class="submenu"><a class="no-link children" href="#"> Categories <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-73" class="submenu-aim sublevel"><li class=""><a href="/public/images/archive/category/360pano/ "> 360 Panorama </a></li><li class=""><a href="/public/images/archive/category/alma/"> ALMA </a></li><li class=""><a href="/public/images/archive/category/apex/"> APEX </a></li><li class=""><a href="/public/images/archive/category/chile/"> Chile </a></li><li class=""><a href="/public/images/archive/category/cosmology/"> Cosmology </a></li><li class=""><a href="/public/images/archive/category/elt/"> ELT </a></li><li class=""><a href="/public/images/archive/category/eso-supernova/"> ESO Supernova </a></li><li class=""><a href="/public/images/archive/category/exoplanets/"> Exoplanets </a></li><li class=""><a href="/public/images/archive/category/fulldome/"> Fulldome </a></li><li class=""><a href="/public/images/archive/category/galaxies/"> Galaxies </a></li><li class=""><a href="/public/images/archive/category/galaxyclusters/"> Galaxy Clusters </a></li><li class=""><a href="/public/images/archive/category/illustrations/"> Illustrations </a></li><li class=""><a href="/public/images/archive/category/lasilla/"> La Silla </a></li><li class=""><a href="/public/images/archive/category/nebulae/"> Nebulae </a></li><li class=""><a href="/public/images/archive/category/paranal/"> Paranal </a></li><li class=""><a href="/public/images/archive/category/peopleandevents/"> People and Events </a></li><li class=""><a href="/public/images/archive/category/premises/"> Premises </a></li><li class=""><a href="/public/images/archive/category/blackholes/"> Quasars and Black Holes </a></li><li class=""><a href="/public/images/archive/category/solarsystem/"> Solar System </a></li><li class=""><a href="/public/images/archive/category/starclusters/"> Star Clusters </a></li><li class=""><a href="/public/images/archive/category/stars/"> Stars </a></li><li class=""><a href="/public/images/archive/category/surveytelescopes/"> Survey Telescopes </a></li></ul></li><li class=""><a href="/public/images/comparisons/"> Image Comparisons </a></li><li class=""><a href="/public/images/imageformats/"> Image Formats </a></li><li class="submenu"><a href="/public/images/potw/"> Picture of the Week <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-98" class="submenu-aim sublevel"><li class=""><a href="/public/images/potw/archive/year/2024/"> 2024 </a></li><li class=""><a href="/public/images/potw/archive/year/2023/"> 2023 </a></li><li class=""><a href="/public/images/potw/archive/year/2022/"> 2022 </a></li><li class=""><a href="/public/images/potw/archive/year/2021/"> 2021 </a></li><li class=""><a href="/public/images/potw/archive/year/2020/"> 2020 </a></li><li class=""><a href="/public/images/potw/archive/year/2019/"> 2019 </a></li><li class=""><a href="/public/images/potw/archive/year/2018/"> 2018 </a></li><li class=""><a href="/public/images/potw/archive/year/2017/"> 2017 </a></li><li class=""><a href="/public/images/potw/archive/year/2016/"> 2016 </a></li><li class=""><a href="/public/images/potw/archive/year/2015/"> 2015 </a></li><li class=""><a href="/public/images/potw/archive/year/2014/"> 2014 </a></li><li class=""><a href="/public/images/potw/archive/year/2013/"> 2013 </a></li><li class=""><a href="/public/images/potw/archive/year/2012/"> 2012 </a></li><li class=""><a href="/public/images/potw/archive/year/2011/"> 2011 </a></li><li class=""><a href="/public/images/potw/archive/year/2010/"> 2010 </a></li><li class=""><a href="/public/images/potw/archive/year/2009/"> 2009 </a></li><li class=""><a href="/public/images/potw/archive/year/2008/"> 2008 </a></li><li class=""><a href="/public/images/potw/archive/year/2007/"> 2007 </a></li></ul></li><li class="submenu"><a href="/public/images/archive/top100/"> Top 100 <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-117" class="submenu-aim sublevel"><li class=""><a href="https://cdn.eso.org/images/top100-large.zip"> Large JPG Zip File (3.5 GB) </a></li><li class=""><a href="https://cdn.eso.org/images/top100-original.zip"> Original TIF Zip File (50 GB) </a></li></ul></li><li class=""><a href="/public/copyright/"> Usage of ESO Images and Videos </a></li><li class=""><a href="/public/images/archive/wallpapers/"> Wallpapers </a></li><li class=""><a href="/public/images/archive/zoomable/"> Zoomable </a></li> </ul> </div> </div> </li> <li><a href="/public/videos/">Videos<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-123" class="submenu-aim"> <li class=""><a href="/public/videos/search/"> Advanced Search </a></li><li class="submenu"><a class="no-link children" href="#"> Categories <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-125" class="submenu-aim sublevel"><li class=""><a href="/public/videos/archive/category/abouteso/"> About ESO </a></li><li class=""><a href="/public/videos/archive/category/alma/"> ALMA </a></li><li class=""><a href="/public/videos/archive/category/apex/"> APEX </a></li><li class=""><a href="/public/videos/archive/category/chasingstarlight/"> Chasing Starlight </a></li><li class=""><a href="/public/videos/archive/category/compilations/"> Compilations </a></li><li class=""><a href="/public/videos/archive/category/cosmology/"> Cosmology </a></li><li class=""><a href="/public/videos/archive/category/elt/"> ELT </a></li><li class=""><a href="/public/videos/archive/category/esocast/"> ESOcast </a></li><li class=""><a href="/public/videos/archive/category/events/"> Events </a></li><li class=""><a href="/public/videos/archive/category/exoplanets/"> Exoplanets </a></li><li class=""><a href="/public/videos/archive/category/featuremovies/"> Feature Movies </a></li><li class=""><a href="/public/videos/archive/category/fulldome/"> Fulldome </a></li><li class=""><a href="/public/videos/archive/category/galaxies/"> Galaxies </a></li><li class=""><a href="/public/videos/archive/category/galaxyclusters/"> Galaxy Clusters </a></li><li class=""><a href="/public/videos/archive/category/lasilla/"> La Silla </a></li><li class=""><a href="/public/videos/archive/category/nebulae/"> Nebulae </a></li><li class=""><a href="/public/videos/archive/category/paranal/"> Paranal </a></li><li class=""><a href="/public/videos/archive/category/premises/"> Premises </a></li><li class=""><a href="/public/videos/archive/category/blackholes/"> Quasars and Black Holes </a></li><li class=""><a href="/public/videos/archive/category/solarsystem/"> Solar System </a></li><li class=""><a href="/public/videos/archive/category/starclusters/"> Star Clusters </a></li><li class=""><a href="/public/videos/archive/category/stars/"> Stars </a></li><li class=""><a href="/public/videos/archive/category/vnr/"> Video News Releases </a></li></ul></li><li class=""><a href="/public/copyright/"> Usage of ESO Videos and Images </a></li><li class=""><a href="/public/videoformats/"> Video Formats </a></li> </ul> </div> </div> </li> <li><a href="/public/news/">News<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-151" class="submenu-aim"> <li class="submenu"><a href="/public/news/"> Press Releases <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-152" class="submenu-aim sublevel"><li class="submenu"><a class="no-link children" href="#"> 2021-2030 <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-153" class="submenu-aim sublevel"><li class=""><a href="/public/news/archive/year/2024/"> 2024 </a></li><li class=""><a href="/public/news/archive/year/2023/"> 2023 </a></li><li class=""><a href="/public/news/archive/year/2022/"> 2022 </a></li><li class=""><a href="/public/news/archive/year/2021/"> 2021 </a></li></ul></li><li class="submenu"><a class="no-link children" href="#"> 2011–2020 <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-158" class="submenu-aim sublevel"><li class=""><a href="/public/news/archive/year/2020/"> 2020 </a></li><li class=""><a href="/public/news/archive/year/2019/"> 2019 </a></li><li class=""><a href="/public/news/archive/year/2018/"> 2018 </a></li><li class=""><a href="/public/news/archive/year/2017/"> 2017 </a></li><li class=""><a href="/public/news/archive/year/2016/"> 2016 </a></li><li class=""><a href="/public/news/archive/year/2015/"> 2015 </a></li><li class=""><a href="/public/news/archive/year/2014/"> 2014 </a></li><li class=""><a href="/public/news/archive/year/2013/"> 2013 </a></li><li class=""><a href="/public/news/archive/year/2012/"> 2012 </a></li><li class=""><a href="/public/news/archive/year/2011/"> 2011 </a></li></ul></li><li class="submenu"><a class="no-link children" href="#"> 2001–2010 <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-169" class="submenu-aim sublevel"><li class=""><a href="/public/news/archive/year/2010/"> 2010 </a></li><li class=""><a href="/public/news/archive/year/2009/"> 2009 </a></li><li class=""><a href="/public/news/archive/year/2008/"> 2008 </a></li><li class=""><a href="/public/news/archive/year/2007/"> 2007 </a></li><li class=""><a href="/public/news/archive/year/2006/"> 2006 </a></li><li class=""><a href="/public/news/archive/year/2005/"> 2005 </a></li><li class=""><a href="/public/news/archive/year/2004/"> 2004 </a></li><li class=""><a href="/public/news/archive/year/2003/"> 2003 </a></li><li class=""><a href="/public/news/archive/year/2002/"> 2002 </a></li><li class=""><a href="/public/news/archive/year/2001/"> 2001 </a></li></ul></li><li class="submenu"><a class="no-link children" href="#"> 1991–2000 <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-180" class="submenu-aim sublevel"><li class=""><a href="/public/news/archive/year/2000/"> 2000 </a></li><li class=""><a href="/public/news/archive/year/1999/"> 1999 </a></li><li class=""><a href="/public/news/archive/year/1998/"> 1998 </a></li><li class=""><a href="/public/news/archive/year/1997/"> 1997 </a></li><li class=""><a href="/public/news/archive/year/1996/"> 1996 </a></li><li class=""><a href="/public/news/archive/year/1995/"> 1995 </a></li><li class=""><a href="/public/news/archive/year/1994/"> 1994 </a></li><li class=""><a href="/public/news/archive/year/1993/"> 1993 </a></li><li class=""><a href="/public/news/archive/year/1992/"> 1992 </a></li><li class=""><a href="/public/news/archive/year/1991/"> 1991 </a></li></ul></li><li class="submenu"><a class="no-link children" href="#"> 1985–1990 <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-191" class="submenu-aim sublevel"><li class=""><a href="/public/news/archive/year/1990/"> 1990 </a></li><li class=""><a href="/public/news/archive/year/1989/"> 1989 </a></li><li class=""><a href="/public/news/archive/year/1988/"> 1988 </a></li><li class=""><a href="/public/news/archive/year/1987/"> 1987 </a></li><li class=""><a href="/public/news/archive/year/1986/"> 1986 </a></li><li class=""><a href="/public/news/archive/year/1985/"> 1985 </a></li></ul></li></ul></li><li class="submenu"><a href="/public/announcements/"> Announcements <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-198" class="submenu-aim sublevel"><li class=""><a href="/public/announcements/archive/year/2024/"> 2024 </a></li><li class=""><a href="/public/announcements/archive/year/2023/"> 2023 </a></li><li class=""><a href="/public/announcements/archive/year/2022/"> 2022 </a></li><li class=""><a href="/public/announcements/archive/year/2021/"> 2021 </a></li><li class=""><a href="/public/announcements/archive/year/2020/"> 2020 </a></li><li class=""><a href="/public/announcements/archive/year/2019/"> 2019 </a></li><li class=""><a href="/public/announcements/archive/year/2018/"> 2018 </a></li><li class=""><a href="/public/announcements/archive/year/2017/"> 2017 </a></li><li class=""><a href="/public/announcements/archive/year/2016/"> 2016 </a></li><li class=""><a href="/public/announcements/archive/year/2015/"> 2015 </a></li><li class=""><a href="/public/announcements/archive/year/2014/"> 2014 </a></li><li class=""><a href="/public/announcements/archive/year/2013/"> 2013 </a></li><li class=""><a href="/public/announcements/archive/year/2012/"> 2012 </a></li><li class=""><a href="/public/announcements/archive/year/2011/"> 2011 </a></li><li class=""><a href="/public/announcements/archive/year/2010/"> 2010 </a></li><li class=""><a href="/public/announcements/archive/year/2009/"> 2009 </a></li></ul></li><li class=""><a href="https://www.eso.org/public/blog/"> ESOblog </a></li><li class=""><a href="/public/announcements/webupdates/"> New on eso.org </a></li><li class="submenu"><a href="/public/outreach/pressmedia/"> Press Room <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-217" class="submenu-aim sublevel"><li class=""><a href="/public/outreach/broadcast/"> Broadcast Services </a></li><li class=""><a href="/public/outreach/pressmedia/mediavisits/"> Media Visits </a></li><li class=""><a href="/public/copyright/"> Copyright Notice </a></li></ul></li><li class="submenu"><a href="/public/newsletters/"> ESO Newsletters <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-221" class="submenu-aim sublevel"><li class=""><a href="/public/newsletters/esonews/"> ESO News </a></li><li class=""><a href="/sci/publications/newsletter/"> ESO Science Newsletter </a></li><li class=""><a href="/public/outreach/newsletters/#2"> ESO Media Newsletter </a></li></ul></li><li class=""><a href="/public/news/pitch-your-research/"> Pitch your Research </a></li> </ul> </div> </div> </li> <li><a href="/public/shop/">ESOshop<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-226" class="submenu-aim"> <li class="submenu"><a href="/public/shop/category/"> Shop Products <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-227" class="submenu-aim sublevel"><li class=""><a href="/public/shop/category/annualreport/"> Annual Reports </a></li><li class=""><a href="/public/shop/category/apparel/"> Apparel </a></li><li class=""><a href="/public/shop/category/book/"> Books </a></li><li class=""><a href="/public/shop/category/brochure/"> Brochures </a></li><li class=""><a href="/public/shop/category/calendar/"> Calendars </a></li><li class=""><a href="/public/shop/category/capjournal/"> CAPjournals </a></li><li class=""><a href="/public/shop/category/conferenceitem/"> Conferences </a></li><li class=""><a href="/public/shop/category/donation/"> Donations </a></li><li class=""><a href="/public/shop/category/media/"> DVDs/Bluray/CDs </a></li><li class=""><a href="/public/shop/category/educationalmaterial/"> Educational Material </a></li><li class=""><a href="/public/shop/category/supernovaactivity/"> ESO Supernova Activities </a></li><li class=""><a href="/public/shop/category/flyer/"> Flyers </a></li><li class=""><a href="/public/shop/category/handout/"> Handouts </a></li><li class=""><a href="/public/shop/category/map/"> Maps </a></li><li class=""><a href="/public/shop/category/merchandise/"> Merchandise </a></li><li class=""><a href="/public/shop/category/messenger/"> Messengers </a></li><li class=""><a href="/public/shop/category/mountedimage/"> Mounted Images </a></li><li class=""><a href="/public/shop/category/postcard/"> Postcards </a></li><li class=""><a href="/public/shop/category/printedposter/"> Posters </a></li><li class=""><a href="/public/shop/category/technicaldocument/"> Reports </a></li><li class=""><a href="/public/shop/category/sticker/"> Stickers </a></li></ul></li><li class=""><a href="/public/shop/cart/"> View shopping cart </a></li><li class=""><a href="/public/shop/checkout/"> Checkout </a></li><li class="submenu"><a href="/public/shopinfo/"> Information <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-251" class="submenu-aim sublevel"><li class=""><a href="/public/shopinfo/bulk_orders/"> Bulk Orders </a></li><li class=""><a href="/public/shopinfo/"> Purchasing Steps </a></li><li class=""><a href="/public/shopinfo/payment/"> Payment </a></li><li class=""><a href="/public/shopinfo/shipping/"> Shipping </a></li><li class=""><a href="/public/shopinfo/shopstaff/"> Staff Shopping </a></li><li class=""><a href="/public/shopinfo/terms/"> Terms & Conditions </a></li></ul></li><li class=""><a href="/public/shop/freeorder/"> Free Orders for Educators and Media </a></li> </ul> </div> </div> </li> <li class="current"><a href="/public/teles-instr/">Telescopes & Instruments<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1 current"> <ul id="submenu-aim-259" class="submenu-aim selected current"> <li class="submenu"><a href="/public/teles-instr/paranal-observatory/"> Paranal Observatory <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-260" class="submenu-aim sublevel"><li class="submenu"><a href="/public/teles-instr/paranal-observatory/vlt/"> Very Large Telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-261" class="submenu-aim sublevel"><li class="submenu"><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/"> VLT Instruments <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-262" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/4lgsf/"> 4LGSF </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/cubes/"> CUBES </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/crires/"> CRIRES </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/crires+/"> CRIRES+ </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/espresso/"> ESPRESSO </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/eris/"> ERIS </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/flames/"> FLAMES </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/fors/"> FORS1 and FORS2 </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/hawk-i/"> HAWK-I </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/isaac/"> ISAAC </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/kmos/"> KMOS </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/mad/"> MAD </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/mavis/"> MAVIS </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/moons/"> MOONS </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/muse/"> MUSE </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/naco/"> NACO </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/sinfoni/"> SINFONI </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/sphere/"> SPHERE </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/uves/"> UVES </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/vimos/"> VIMOS </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/vtl-test-cameras/"> VLT Test Cameras </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/visir/"> VISIR </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/x-shooter/"> X-shooter </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/paranal-observatory/vlt/vlt-names/"> VLT Unit Telescopes Names <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-286" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-names/antu/"> Antu </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-names/kueyen/"> Kueyen </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-names/melipal/"> Melipal </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-names/yepun/"> Yepun </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/paranal-observatory/vlt/vlti/"> VLT Interferometer <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-291" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/gravity+/"> GRAVITY+ </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/gravity/"> GRAVITY </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/matisse/"> MATISSE </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/naomi/"> NAOMI </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/pionier/"> PIONIER </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/amber/"> AMBER </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/midi/"> MIDI </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/vlt-instr/vinci/"> VINCI </a></li></ul></li><li class=""><a href="/public/teles-instr/paranal-observatory/vlt/auxiliarytelescopes/"> Auxiliary Telescopes </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/paranal-observatory/surveytelescopes/"> Survey Telescopes <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-301" class="submenu-aim sublevel"><li class="submenu"><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vista/"> VISTA <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-302" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vista/mirror/"> The VISTA mirror </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vista/camera/"> VIRCAM </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vista/4most/"> 4MOST </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vista/surveys/"> The VISTA surveys </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vista/consortium/"> The VISTA consortium </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vst/"> VST <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-308" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vst/mirror/"> The VST mirrors </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vst/camera/"> OmegaCAM </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/surveytelescopes/vst/surveys/"> The VST surveys </a></li></ul></li></ul></li><li class=""><a href="/public/teles-instr/paranal-observatory/speculoos/"> SPECULOOS </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/ngts/"> NGTS </a></li><li class=""><a href="/public/teles-instr/paranal-observatory/ctao/"> Cherenkov Telescope Array Observatory </a></li></ul></li><li class="submenu current"><a href="/public/teles-instr/lasilla/"> La Silla Observatory <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-315" class="submenu-aim sublevel selected current"><li class="submenu"><a href="/public/teles-instr/lasilla/swedish/"> Swedish–ESO Submillimetre Telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-316" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/swedish/simba/"> SIMBA </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/lasilla/ntt/"> New Technology Telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-318" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/ntt/efosc2/"> EFOSC2 </a></li><li class=""><a href="/public/teles-instr/lasilla/ntt/emmi/"> EMMI </a></li><li class=""><a href="/public/teles-instr/lasilla/ntt/irspec/"> IRSPEC </a></li><li class=""><a href="/public/teles-instr/lasilla/ntt/sofi/"> SOFI </a></li><li class=""><a href="/public/teles-instr/lasilla/ntt/soxs/"> SOXS </a></li><li class=""><a href="/public/teles-instr/lasilla/ntt/susi2/"> SUSI and SUSI2 </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/lasilla/36/"> ESO 3.6-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-325" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/36/adonis/"> ADONIS </a></li><li class=""><a href="/public/teles-instr/lasilla/36/caspec/"> CASPEC </a></li><li class=""><a href="/public/teles-instr/lasilla/36/irspec/"> IRSPEC </a></li><li class=""><a href="/public/teles-instr/lasilla/36/harps/"> HARPS </a></li><li class=""><a href="/public/teles-instr/lasilla/36/mefos/"> MEFOS </a></li><li class=""><a href="/public/teles-instr/lasilla/36/nirps/"> NIRPS </a></li><li class=""><a href="/public/teles-instr/lasilla/36/optopus/"> OPTOPUS </a></li><li class=""><a href="/public/teles-instr/lasilla/36/timmi2/"> TIMMI/2 </a></li><li class=""><a href="/public/teles-instr/lasilla/36/36-infrared-photometer-spectrophotometer/"> Infrared Photometer/Spectrophotometer </a></li><li class=""><a href="/public/teles-instr/lasilla/36/36-standard-photometer/"> Standard Photometer </a></li><li class=""><a href="/public/teles-instr/lasilla/36/infrared-specklegraph/"> Infrared Specklegraph </a></li><li class=""><a href="/public/teles-instr/lasilla/36/infrared-speckle-interferometer/"> Infrared Speckle Interferometer </a></li><li class=""><a href="/public/teles-instr/lasilla/36/efosc/"> EFOSC </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/lasilla/mpg22/"> MPG/ESO 2.2-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-339" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/mpg22/feros/"> FEROS </a></li><li class=""><a href="/public/teles-instr/lasilla/mpg22/grond/"> GROND </a></li><li class=""><a href="/public/teles-instr/lasilla/mpg22/irac2/"> IRAC & IRAC2 </a></li><li class=""><a href="/public/teles-instr/lasilla/mpg22/pisco/"> PISCO </a></li><li class=""><a href="/public/teles-instr/lasilla/mpg22/wfi/"> WFI </a></li><li class=""><a href="/public/teles-instr/lasilla/mpg22/infrared-photometer-spectrophotometer/"> Infrared Photometer/Spectrophotometer </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/lasilla/swiss/"> Swiss 1.2-metre Leonhard Euler Telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-346" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/swiss/coralie/"> CORALIE </a></li></ul></li><li class=""><a href="/public/teles-instr/lasilla/rem/"> Rapid Eye Mount telescope </a></li><li class=""><a href="/public/teles-instr/lasilla/trappist/"> TRAnsiting Planets and PlanetesImals Small Telescope–South </a></li><li class="submenu current"><a href="/public/teles-instr/lasilla/danish154/"> Danish 1.54-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-350" class="submenu-aim sublevel selected current current-leaf"><li class=""><a href="/public/teles-instr/lasilla/danish154/coravel/"> CORAVEL </a></li><li class=""><a href="/public/teles-instr/lasilla/danish154/dfosc/"> DFOSC </a></li><li class=""><a href="/public/teles-instr/lasilla/danish154/ccd/"> CCD camera </a></li><li class=" current current-leaf"><a href="/public/teles-instr/lasilla/danish154/hb-photometer/"> Hβ Photometer </a></li><li class=""><a href="/public/teles-instr/lasilla/danish154/two-channel-photometer/"> Two-Channel Photometer </a></li><li class=""><a href="/public/teles-instr/lasilla/danish154/four-channel-photometer/"> Four-Channel Photometer </a></li><li class=""><a href="/public/teles-instr/lasilla/danish154/six-channel-photometer/"> Six-Channel uvby-Hβ Photometer </a></li></ul></li><li class=""><a href="/public/teles-instr/lasilla/tarot/"> Télescope à Action Rapide pour les Objets Transitoires </a></li><li class=""><a href="/public/teles-instr/lasilla/1mschmidt/"> ESO 1-metre Schmidt telescope </a></li><li class="submenu"><a href="/public/teles-instr/lasilla/152metre/"> ESO 1.52-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-360" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/152metre/bandc/"> Boller and Chivens Spectrograph </a></li><li class=""><a href="/public/teles-instr/lasilla/152metre/coude/"> Coudé Spectrograph </a></li><li class=""><a href="/public/teles-instr/lasilla/152metre/echelec/"> ECHELEC </a></li><li class=""><a href="/public/teles-instr/lasilla/152metre/rv-cass-spectrograph/"> RV Cass Spectrograph </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/lasilla/1metre/"> ESO 1-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-365" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/1metre/fideos/"> FIDEOS </a></li><li class=""><a href="/public/teles-instr/lasilla/1metre/infrared-photometer/"> Infrared Photometer </a></li><li class=""><a href="/public/teles-instr/lasilla/1metre/single-channel-photometer/"> Single-Channel Photometer </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/lasilla/05metre/"> ESO 0.5-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-369" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/05metre/single-channel-photometer/"> Single-Channel Photometer </a></li><li class=""><a href="/public/teles-instr/lasilla/05metre/double-channel-photometer/"> Double-Channel Photometer </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/lasilla/coude/"> Coudé Auxiliary Telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-372" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/coude/ces/"> CES </a></li></ul></li><li class=""><a href="/public/teles-instr/lasilla/marly/"> MarLy 1-metre telescope </a></li><li class="submenu"><a href="/public/teles-instr/lasilla/09metre/"> Dutch 0.9-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-375" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/09metre/walraven/"> Walraven Photometer </a></li></ul></li><li class=""><a href="/public/teles-instr/lasilla/t70/"> Swiss T70 telescope </a></li><li class="submenu"><a href="/public/teles-instr/lasilla/bochum/"> Bochum 0.61-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-378" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/bochum/bochum-scanner/"> Bochum Scanner </a></li><li class=""><a href="/public/teles-instr/lasilla/bochum/bochum-photometer/"> Bochum Photometer </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/lasilla/danish05/"> Danish 0.5-metre telescope <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-381" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/lasilla/danish05/danish-two-channel-hb-photometer/"> Two-Channel Hβ Photometer </a></li><li class=""><a href="/public/teles-instr/lasilla/danish05/danish-four-channel-uvby-photometer/"> Four-Channel uvby Photometer </a></li><li class=""><a href="/public/teles-instr/lasilla/danish05/danish-six-channel-uvby-hb-photometer/"> Six-Channel uvby–Hβ Photometer </a></li></ul></li><li class=""><a href="/public/teles-instr/lasilla/gpo/"> Grand Prisme Objectif telescope </a></li><li class=""><a href="/public/teles-instr/lasilla/swiss04/"> Swiss 0.4-metre telescope </a></li><li class=""><a href="/public/teles-instr/lasilla/marseille/"> Marseille 0.36-metre telescope </a></li><li class=""><a href="/public/teles-instr/lasilla/grb/"> GRB Monitoring System </a></li><li class=""><a href="/public/teles-instr/lasilla/mascara/"> MASCARA </a></li><li class=""><a href="/public/teles-instr/lasilla/blackgem/"> BlackGEM </a></li><li class=""><a href="/public/teles-instr/lasilla/extra/"> ExTrA </a></li><li class=""><a href="/public/teles-instr/lasilla/test-bed/"> Test-Bed Telescope </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/apex/"> APEX <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-393" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/apex/apex-2a/"> APEX–2A </a></li><li class=""><a href="/public/teles-instr/apex/artemis/"> ArTéMiS </a></li><li class=""><a href="/public/teles-instr/apex/aszca/"> ASZCa </a></li><li class=""><a href="/public/teles-instr/apex/champ-plus/"> CHAMP+ </a></li><li class=""><a href="/public/teles-instr/apex/concerto/"> CONCERTO </a></li><li class=""><a href="/public/teles-instr/apex/flash/"> FLASH </a></li><li class=""><a href="/public/teles-instr/apex/flash-plus/"> FLASH+ </a></li><li class=""><a href="/public/teles-instr/apex/laboca/"> LABOCA </a></li><li class=""><a href="/public/teles-instr/apex/mpi_11thz/"> MPI_1.1THz </a></li><li class=""><a href="/public/teles-instr/apex/p-artemis/"> P-ArTéMiS </a></li><li class=""><a href="/public/teles-instr/apex/pi230/"> PI230 </a></li><li class=""><a href="/public/teles-instr/apex/polka/"> PolKa </a></li><li class=""><a href="/public/teles-instr/apex/saboca/"> SABOCA </a></li><li class=""><a href="/public/teles-instr/apex/sepia/"> SEPIA </a></li><li class=""><a href="/public/teles-instr/apex/shefi/"> SHeFI </a></li></ul></li><li class="submenu"><a href="/public/teles-instr/alma/"> ALMA <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-409" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/alma/antennas/"> Antennas </a></li><li class=""><a href="/public/teles-instr/alma/transporters/"> Transporters </a></li><li class=""><a href="/public/teles-instr/alma/interferometry/"> Interferometry </a></li><li class=""><a href="/public/teles-instr/alma/receiver-bands/"> Receiver Bands </a></li><li class=""><a href="/public/teles-instr/alma/residencia/"> ALMA Residencia </a></li></ul></li><li class=""><a href="/public/teles-instr/elt/"> ELT </a></li><li class="submenu"><a href="/public/teles-instr/technology/"> Technology for Telescopes <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-416" class="submenu-aim sublevel"><li class=""><a href="/public/teles-instr/technology/active_optics/"> Active Optics </a></li><li class=""><a href="/public/teles-instr/technology/adaptive_optics/"> Adaptive Optics </a></li><li class=""><a href="/public/teles-instr/technology/ifu/"> Integral Field Units </a></li><li class=""><a href="/public/teles-instr/technology/interferometry/"> Interferometry </a></li><li class=""><a href="/public/teles-instr/technology/spectroscopy/"> Spectroscopy </a></li><li class=""><a href="/public/teles-instr/technology/polarimetry/"> Polarimetry </a></li></ul></li><li class=""><a href="/public/teles-instr/instruments/"> Instruments </a></li> </ul> </div> </div> </li> <li><a href="/public/science/">Discoveries<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-424" class="submenu-aim"> <li class=""><a href="/public/science/key-discoveries/"> ESO Key Astronomical Discoveries </a></li><li class=""><a href="/public/science/exoplanets/"> Exoplanets </a></li><li class=""><a href="/public/science/gravitationalwaves/"> Gravitational Wave Sources </a></li><li class="submenu"><a class="no-link children" href="#"> Black Holes <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-428" class="submenu-aim sublevel"><li class=""><a href="https://www.eso.org/public/science/event-horizon/"> First image of a black hole </a></li><li class=""><a href="https://www.eso.org/public/science/EHT-MilkyWay/"> First image of the Milky Way central black hole </a></li><li class=""><a href="https://www.eso.org/public/science/gc/"> More about the black hole at the galactic centre </a></li></ul></li><li class=""><a href="/public/science/grb/"> Gamma-Ray Bursts </a></li><li class=""><a href="/public/science/archive/"> Science Archive </a></li> </ul> </div> </div> </li> <li><a href="/public/events/">Events<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-434" class="submenu-aim"> <li class=""><a href="/public/events/press-evt/"> Press Events </a></li><li class="submenu"><a href="/public/events/special-evt/"> Special Events <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-436" class="submenu-aim sublevel"><li class=""><a href="https://www.eso.org/public/events/special-evt/60years/"> ESO at 60 </a></li><li class=""><a href="/public/events/special-evt/eeltblast/"> ELT Groundbreaking </a></li><li class=""><a href="/public/events/special-evt/cafe-and-kosmos/"> Café & Kosmos in Munich </a></li><li class=""><a href="/public/events/special-evt/awesome-universe/"> Awesome Universe </a></li><li class=""><a href="/public/events/special-evt/100ha/"> 100 Hours of Astronomy </a></li><li class=""><a href="/public/events/special-evt/theeye/"> The Eye 3D </a></li><li class=""><a href="/public/events/special-evt/imax-hidden-universe/"> IMAX® 3D Film Hidden Universe </a></li><li class=""><a href="/public/outreach/bond/"> Bond at Paranal </a></li></ul></li><li class="submenu"><a href="/public/events/exhibitions/"> Exhibitions <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-445" class="submenu-aim sublevel"><li class=""><a href="/public/events/exhibitions/perma_exhibitions/"> ESO Permanent Exhibitions </a></li><li class=""><a href="https://www.esof.eu/"> EuroScience Open Forum (ESOF) </a></li></ul></li><li class="submenu"><a href="/public/events/astro-evt/"> Astronomical Events <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-448" class="submenu-aim sublevel"><li class=""><a href="/public/events/astro-evt/solareclipse2019/"> Total Solar Eclipse 2019 </a></li><li class=""><a href="/public/events/astro-evt/mcnaught2007/"> The Comet McNaught 2007 </a></li><li class=""><a href="/public/events/astro-evt/deepimpact/"> Deep Impact - 04.07.2005 </a></li><li class=""><a href="https://www.eso.org/public/outreach/eduoff/vt-2004/"> The Venus Transit - 08.11.2004 </a></li><li class=""><a href="/public/events/astro-evt/leonids99/"> The Leonids - 17.11.1999 </a></li><li class=""><a href="/public/events/astro-evt/eclipse99/"> Solar Eclipse at ESO HQ - 11.08.1999 </a></li><li class=""><a href="/public/events/astro-evt/leonids98/"> The Leonids - 11.1998 </a></li><li class=""><a href="/public/events/astro-evt/pathfinder/"> Mars Pathfinder - 1997 </a></li><li class=""><a href="/public/events/astro-evt/hyakutake/"> Comet Hyakutake - 1997 </a></li><li class=""><a href="/public/events/astro-evt/sl9/"> SL-9 and Jupiter - 1994 </a></li><li class=""><a href="/public/events/astro-evt/hale-bopp/"> Comet Hale Bopp - 1994 </a></li></ul></li> </ul> </div> </div> </li> <li><a href="/public/outreach/">Outreach<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-460" class="submenu-aim"> <li class="submenu"><a href="/public/outreach/eduoff/"> Education <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-461" class="submenu-aim sublevel"><li class=""><a href="/public/products/education/"> Educational Material </a></li><li class=""><a href="https://www.scienceinschool.org/" target="_blank" rel="noopener noreferrer"> Science in School </a></li><li class=""><a href="/public/outreach/eduoff/teacherschools/"> Teacher Schools </a></li><li class="submenu"><a href="/public/outreach/eduoff/prev-programmes/"> Previous Programmes <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-465" class="submenu-aim sublevel"><li class=""><a href="https://www.eso.org/public/outreach/eduoff/prev-programmes/catch-a-star/"> Catch a Star </a></li><li class=""><a href="/public/outreach/eduoff/liu/"> Life in the Universe </a></li><li class=""><a href="/public/outreach/eduoff/pos/"> Physics On Stage </a></li></ul></li><li class=""><a href="http://kids.alma.cl/?lang=en"> ALMA Kids </a></li></ul></li><li class="submenu"><a href="/public/outreach/partnerships/"> Partnerships <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-470" class="submenu-aim sublevel"><li class=""><a href="/public/outreach/partnerships/translators/"> Volunteer Translators </a></li><li class=""><a href="/public/outreach/partnerships/eson/"> ESO Science Outreach Network </a></li><li class="submenu"><a href="/public/outreach/partnerships/chile/"> Collaborations in Chile <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-473" class="submenu-aim sublevel"><li class=""><a href="/public/outreach/partnerships/chile/2010/"> 2010 </a></li><li class=""><a href="/public/outreach/partnerships/chile/2009/"> 2009 </a></li></ul></li><li class=""><a href="/public/outreach/partnerships/organisations/"> ESO Outreach Partner Organisations </a></li><li class=""><a href="/public/outreach/partnerships/educators/"> Informal Educators </a></li><li class=""><a href="/public/outreach/partnerships/photo-ambassadors/"> ESO Photo Ambassadors </a></li><li class=""><a href="/public/outreach/partnerships/music-ambassadors/"> ESO Music Ambassadors </a></li></ul></li><li class=""><a href="https://www.eso.org/public/outreach/first-picture-of-a-black-hole/blog/"> Taking the First Picture of a Black Hole </a></li><li class=""><a href="/public/outreach/gems/"> Cosmic Gems </a></li><li class=""><a href="/public/outreach/social/"> Social Media </a></li><li class=""><a href="/public/outreach/for_planetariums/"> For Planetariums </a></li><li class=""><a href="https://www.eso.org/public/outreach/webcams/"> Webcams </a></li><li class=""><a href="/public/outreach/your_eso_pictures/"> Your ESO Pictures </a></li><li class=""><a href="/public/outreach/astroprize/"> European Astronomy Journalism Prize </a></li><li class="submenu"><a href="/public/outreach/department/"> Our Team <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-487" class="submenu-aim sublevel"><li class=""><a href="/public/outreach/department/students/"> Students and Visitors </a></li><li class=""><a href="https://supernova.eso.org/join-us/"> Join us </a></li></ul></li><li class=""><a href="https://supernova.eso.org/"> ESO Supernova </a></li><li class=""><a href="/public/outreach/art/"> Art at ESO </a></li><li class=""><a href="/public/outreach/data2dome/"> Data2Dome </a></li><li class=""><a href="https://www.eso.org/public/blog/"> ESOblog </a></li><li class=""><a href="/public/outreach/starsateso/"> Stars@ESO </a></li><li class=""><a href="/public/outreach/ai-disclaimer/"> AI Disclaimer </a></li> </ul> </div> </div> </li> <li><a href="/public/products/">Products<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-496" class="submenu-aim"> <li class="submenu"><a class="no-link children" href="#"> Audiovisual and multimedia <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-497" class="submenu-aim sublevel"><li class=""><a href="/public/products/models3d/"> 3D models </a></li><li class=""><a href="/public/products/applications/"> Apps </a></li><li class=""><a href="/public/products/media/"> DVDs and CDs </a></li><li class=""><a href="/public/products/imaxfilms/"> IMAX movies </a></li><li class=""><a href="/public/products/minisites/"> Mini-sites </a></li><li class=""><a href="/public/products/music/"> Music </a></li><li class=""><a href="/public/products/planetariumshows/"> Planetarium shows </a></li><li class=""><a href="/public/products/presentations/"> Presentations </a></li><li class=""><a href="/public/products/soundscapes/"> Soundscapes </a></li><li class=""><a href="https://www.eso.org/public/products/virtualbackgrounds/"> Virtual Backgrounds </a></li><li class=""><a href="/public/products/virtualtours/"> Virtual Tours </a></li></ul></li><li class="submenu"><a class="no-link children" href="#"> Periodicals <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-509" class="submenu-aim sublevel"><li class=""><a href="/public/products/messengers/"> Messenger </a></li><li class=""><a href="/public/products/capjournals/"> CAPjournal </a></li><li class=""><a href="/public/products/schools/"> Science in School </a></li></ul></li><li class="submenu"><a class="no-link children" href="#"> Print products <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-513" class="submenu-aim sublevel"><li class=""><a href="/public/products/annualreports/"> Annual Reports </a></li><li class=""><a href="/public/products/books/"> Books </a></li><li class=""><a href="/public/products/brochures/"> Brochures </a></li><li class=""><a href="/public/products/bulletins/"> Bulletins </a></li><li class=""><a href="/public/products/calendars/"> Calendars </a></li><li class=""><a href="/public/products/conf_posters/"> Conference posters </a></li><li class=""><a href="/public/products/flyers/"> Flyers </a></li><li class=""><a href="/public/products/handouts/"> Handouts </a></li><li class=""><a href="/public/products/maps/"> Maps </a></li><li class=""><a href="/public/products/presskits/"> Press kits </a></li><li class=""><a href="/public/products/reports/"> Reports </a></li><li class=""><a href="/public/products/postcards/"> Postcards </a></li><li class=""><a href="/public/products/stickers/"> Stickers </a></li><li class=""><a href="/public/products/print_posters/"> Printed posters </a></li><li class=""><a href="/public/products/papermodels/"> Paper models </a></li></ul></li><li class="submenu"><a href="/public/products/merchandise/"> Merchandise <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-529" class="submenu-aim sublevel"><li class=""><a href="/public/products/merchandise/"> Merchandise </a></li><li class=""><a href="/public/products/apparel/"> Apparel </a></li><li class=""><a href="/public/products/mountedimages/"> Mounted images </a></li><li class=""><a href="/public/products/stationery/"> Stationery </a></li></ul></li><li class="submenu"><a class="no-link children" href="#"> Electronic products <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-534" class="submenu-aim sublevel"><li class=""><a href="/public/products/electroniccards/"> Electronic cards </a></li><li class=""><a href="/public/products/elec_posters/"> Electronic posters </a></li><li class=""><a href="/public/products/epublications/"> ePublications </a></li><li class=""><a href="https://www.eso.org/public/products/virtualbackgrounds/"> Virtual Backgrounds </a></li></ul></li><li class=""><a href="/public/products/education/"> Educational material </a></li><li class=""><a href="/public/products/exhibitions/"> Exhibition material </a></li><li class=""><a href="/public/products/logos/"> Logos </a></li><li class=""><a href="/public/shop/"> Order in ESOshop </a></li> </ul> </div> </div> </li> <li><a href="/public/industry/">Business@ESO<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-543" class="submenu-aim"> <li class=""><a href="/public/industry/cp.html"> Procurement at ESO </a></li><li class=""><a href="https://www.eso.org/public/industry/events/"> Industry Events </a></li><li class="submenu"><a href="/public/industry/techtrans/"> Technology Transfer <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-546" class="submenu-aim sublevel"><li class=""><a href="/public/industry/techtrans/technology-developed-by-industry-or-institutes/"> Technology Developed by Industries </a></li><li class=""><a href="/public/industry/techtrans/develeso/"> Novel technologies by ESO </a></li><li class=""><a href="/public/industry/techtrans/developments/"> ESO know-how </a></li></ul></li><li class="submenu"><a href="/public/industry/projects/"> Future Projects <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-550" class="submenu-aim sublevel"><li class=""><a href="/public/industry/projects/elt/"> Working with the ELT </a></li></ul></li><li class="submenu"><a href="/public/industry/safety.html"> Safety <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-552" class="submenu-aim sublevel"><li class=""><a href="/public/industry/safety/emergency.html"> Emergency & Evacuation </a></li><li class=""><a href="/public/industry/safety/traffic.html"> Traffic & Parking at ESO </a></li><li class=""><a href="/public/industry/safety/contractors.html"> Contractors at ESO </a></li></ul></li><li class=""><a href="/public/industry/contact/"> Contact Information </a></li> </ul> </div> </div> </li> <li><a href="https://recruitment.eso.org/">Career Opportunities<span class="fa fa-angle-down level0-children-arrows"></span></a> <span class="mobile-children"> <span class="fa fa-angle-down"></span> </span> <div class="level1-wrapper"> <div class="level1"> <ul id="submenu-aim-557" class="submenu-aim"> <li class=""><a href="https://recruitment.eso.org/"> Recruitment </a></li><li class="submenu"><a href="/public/jobs/conditions/"> Employment Conditions <span class="desktop-children topmenu-arrow fa fa-angle-right"></span></a><span class="mobile-children"><span class="fa fa-angle-down"></span></span><ul id="submenu-aim-559" class="submenu-aim sublevel"><li class=""><a href="/public/jobs/conditions/intstaff/"> International Staff Members </a></li><li class=""><a href="/public/jobs/conditions/localstaff/"> Local Staff Members (Spanish / English) </a></li><li class=""><a href="/public/jobs/conditions/fellows/"> Fellows </a></li><li class=""><a href="/public/jobs/conditions/students/"> Students </a></li><li class=""><a href="/public/jobs/conditions/paidassoc/"> Paid Associates </a></li></ul></li><li class=""><a href="/public/jobs/working-at-eso/"> Working at ESO </a></li><li class=""><a href="/public/jobs/other-information/"> Other Information </a></li><li class=""><a href="/public/jobs/how_to_use/"> How to use this site </a></li> </ul> </div> </div> </li> </ul> </div> </nav> <div id="content" class=""> <div id="eso-side-logo"> <a href="/public/"> <div data-spy="affix" class="affix"> <div class="sprites-esologo"></div> <span>European<br>Southern<br>Observatory</span> </div> </a> </div> <div class="container " id="body"> <div class="row no-page"> <div class="col-md-12"> </div> </div> <div class="row page"> <div class="col-md-12 one-column"> <div id="edit-info-block"> <div id="page-edit-success" class="alert alert-success alert-dismissible" role="alert" style="display: none"> <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">×</span></button> Page saved successfully </div> <div id="page-edit-failure" class="alert alert-danger alert-dismissible" role="alert" style="display: none"> <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">×</span></button> Couldn't save page :( Please try again. </div> </div> <div class='page-content'> <div id="editable-content"> <h1>H<sub>β</sub> Photometer at the Danish 1.54-m</h1> <div class="row"> <div class="col-md-8"> <p dir="ltr">The H<sub>β</sub> Photometer was mounted on the instrument adaptor at the Cassegrain focus of the <a href="http://www.eso.org/public/teles-instr/lasilla/danish154/">Danish 1.54-metre telescope</a> in 1979. This two-channel photometer allowed simultaneous measurements of the <a href="https://en.wikipedia.org/wiki/Balmer_series">H<sub>β</sub> line</a> through a narrow (λ<sub>HβN</sub> = 486.4 nm) and a wide filter (λ<sub>HβW</sub> = 487 nm). By using a <a href="https://en.wikipedia.org/wiki/Neutral-density_filter">neutral-density filter</a> it was also possible to measure bright standard stars fainter than V=4.0 (without the neutral-density filter) or V=1.0 (with the neutral-density filter).</p> <p dir="ltr">Six diaphragms with different diameters (100, 30, 20, 10, 7 and 4 arcseconds) were available on a wheel that could be rotated by pushing a button on an auxiliary instrument control rack. The data output was saved on paper tape in <a href="https://en.wikipedia.org/wiki/ASCII">ASCII</a>.</p> <p dir="ltr">The H<sub>β</sub> Photometer was decommissioned in the 1980s.</p> </div> <div class="col-md-4"> <table class="table table-bordered" width="100%"> <tbody> <tr> <td> <h3>H<sub>β</sub> Photometer</h3> <p><small>This table lists the global capabilities of the instrument.<br /></small></p> <table class="table"> <tbody> <tr> <td width="30" valign="top"><strong>Location:</strong></td> <td valign="top">Decommissioned</td> </tr> <tr> <td width="30" valign="top"><strong>Telescope:</strong></td> <td valign="top"><a href="https://www.eso.org/public/teles-instr/lasilla/danish154/">Danish 1.54-m telescope</a></td> </tr> <tr> <td valign="top"><strong>Focus:</strong></td> <td valign="top">Cassegrain<br /></td> </tr> <tr> <td valign="top"><strong>Type:</strong></td> <td valign="top">Photometer</td> </tr> <tr> <td valign="top"><strong>Wavelength range:</strong></td> <td valign="top">486.4 nm; 487 nm</td> </tr> <tr> <td valign="top"><strong>Spatial resolution:</strong></td> <td valign="top"><br /></td> </tr> <tr> <td valign="top"><strong>Spectral resolution:</strong></td> <td valign="top"><br /></td> </tr> <tr> <td valign="top"><strong>First light:</strong></td> <td valign="top">1979</td> </tr> <tr> <td valign="top"><strong>Science goal:</strong></td> <td valign="top">Stellar photometry</td> </tr> <tr> <td valign="top"><strong>Images taken with the instrument:</strong></td> <td valign="top">N/A</td> </tr> <tr> <td valign="top"><strong>Images of the <strong>instrument</strong>:</strong></td> <td valign="top">N/A</td> </tr> <tr> <td valign="top"><strong>Press Releases with the <strong>instrument</strong>:</strong></td> <td valign="top">N/A</td> </tr> <tr> <td valign="top"><strong>Consortium:</strong></td> <td valign="top"> <ul> <li dir="ltr"><a href="https://www.ku.dk/" target="_blank"> University of Copenhagen</a></li> <li dir="ltr">ESO</li> </ul> <span> </span></td> </tr> </tbody> </table> </td> </tr> </tbody> </table> </div> </div> </div> </div> </div> </div> </div>  <div class="row footernote"> <div class="col-xs-12 col-md-3"> <a href="mailto:information@eso.org">Send us your comments!</a> </div> <div class="col-xs-12 col-md-3"> <a href="/public/outreach/newsletters/esonews/">Subscribe to receive news from ESO in your language</a> </div> <div class="col-xs-12 col-md-3"> <a href="https://www.cdn77.com">Accelerated by CDN77</a> </div> <div class="col-xs-12 col-md-3"> <a href="/public/about-eso/privacy/">Terms & Conditions</a> </div> </div> <link href="/public/archives/djp/css/extras.d3e54451ebbb.css" rel="stylesheet" type="text/css" /> <script type="text/javascript">var MEDIA_URL = "/public/archives/"</script> <script type="text/javascript" src="/public/archives/djp/js/main.04a7335af5a0.js" charset="utf-8"></script> </div>  <div id="social-share" class="hidden-print"> <div class="link facebook" data-toggle="tooltip" data-placement="right" title="Share on Facebook"> <a href="https://www.facebook.com/sharer/sharer.php?u=https://www.eso.org/public/teles-instr/lasilla/danish154/hb-photometer/" target="_blank" rel="noopener noreferrer"><i class="fa-brands fa-facebook-f" aria-hidden="true"></i></a> </div> <div class="link twitter" data-toggle="tooltip" data-placement="right" title="Share on X/Twitter"> <a href="https://twitter.com/intent/tweet?url=https://www.eso.org/public/teles-instr/lasilla/danish154/hb-photometer/&text=The Danish 1.54-metre Hβ Photometer&via=ESO" target="_blank" rel="noopener noreferrer"><i class="fa-brands fa-x-twitter"></i></i></a> </div> <div class="link pinterest" data-toggle="tooltip" data-placement="right" title="Share on Pinterest"> <a href="https://pinterest.com/pin/create/button/?url=https://www.eso.org/public/teles-instr/lasilla/danish154/hb-photometer/&media=&description=The Danish 1.54-metre Hβ Photometer" target="_blank" rel="noopener noreferrer"><i class="fa-brands fa-pinterest-p" aria-hidden="true"></i></a> </div> <div class="link print" data-toggle="tooltip" data-placement="right" title="Print"> <a href="javascript:window.print()" target="_blank" rel="noopener noreferrer"><i class="fa fa-print" aria-hidden="true"></i></a> </div> <div class="link email" data-toggle="tooltip" data-placement="right" title="Share by email"> <a href="mailto:%20?subject=ESO — The Danish 1.54-metre Hβ Photometer&body=https://www.eso.org/public/teles-instr/lasilla/danish154/hb-photometer/" target="_blank" rel="noopener noreferrer"><i class="fa-regular fa-envelope" aria-hidden="true"></i></a> </div> </div> <script> $('[data-toggle="tooltip"]').tooltip(); </script> <input type='hidden' name='csrfmiddlewaretoken' value='nAw2NqGcNPxDW0jFvwvpP8pVSa4TjHNA4QvzjGvcr5wviivwNpnD2F7YwXySAwnj' /> </body> </html>

CINXE.COM

The Danish 1.54-metre Hβ Photometer | ESO