CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-sticky-header-enabled vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Mount Wilson Observatory - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-sticky-header-enabled vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"d057aa3d-63f8-4008-82df-b9566dbfac1d","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Mount_Wilson_Observatory","wgTitle":"Mount Wilson Observatory","wgCurRevisionId":1269285229,"wgRevisionId":1269285229,"wgArticleId":213583,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Pages using gadget WikiMiniAtlas","Webarchive template wayback links","Articles with short description","Short description is different from Wikidata","Use mdy dates from October 2023","Coordinates on Wikidata","Articles using Infobox observatory using locally defined parameters","Commons category link from Wikidata","Astronomical observatories in California","Educational buildings in Los Angeles County, California","San Gabriel Mountains", "San Gabriel Mountains National Monument","History of Pasadena, California","Landmarks in Los Angeles","Myron Hunt buildings","Edwin Hubble"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Mount_Wilson_Observatory","wgRelevantArticleId":213583,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":40000,"wgCoordinates":{"lat":34.22503,"lon":-118.05719},"wgEditSubmitButtonLabelPublish":true,"wgULSPosition": "interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q466863","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=[ "ext.cite.ux-enhancements","mediawiki.page.media","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.gadget.WikiMiniAtlas","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.17"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/2/20/Chara-2000-09-15.JPG/1200px-Chara-2000-09-15.JPG"> <meta property="og:image:width" content="1200"> <meta property="og:image:height" content="900"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/2/20/Chara-2000-09-15.JPG/800px-Chara-2000-09-15.JPG"> <meta property="og:image:width" content="800"> <meta property="og:image:height" content="600"> <meta property="og:image" content="https://upload.wikimedia.org/wikipedia/commons/thumb/2/20/Chara-2000-09-15.JPG/640px-Chara-2000-09-15.JPG"> <meta property="og:image:width" content="640"> <meta property="og:image:height" content="480"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Mount Wilson Observatory - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/Mount_Wilson_Observatory"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Mount_Wilson_Observatory&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/Mount_Wilson_Observatory"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Mount_Wilson_Observatory rootpage-Mount_Wilson_Observatory skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" title="Main menu" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-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-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li><li id="n-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages"><span>Special pages</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-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-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=Mount+Wilson+Observatory" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=Mount+Wilson+Observatory" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-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-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=Mount+Wilson+Observatory" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=Mount+Wilson+Observatory" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-Solar_telescopes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Solar_telescopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Solar telescopes</span> </div> </a> <button aria-controls="toc-Solar_telescopes-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 Solar telescopes subsection</span> </button> <ul id="toc-Solar_telescopes-sublist" class="vector-toc-list"> <li id="toc-Snow_Solar_Telescope" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Snow_Solar_Telescope"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.1</span> <span>Snow Solar Telescope</span> </div> </a> <ul id="toc-Snow_Solar_Telescope-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-60-foot_Solar_Tower" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#60-foot_Solar_Tower"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2</span> <span>60-foot Solar Tower</span> </div> </a> <ul id="toc-60-foot_Solar_Tower-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-150-foot_Solar_Tower" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#150-foot_Solar_Tower"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.3</span> <span>150-foot Solar Tower</span> </div> </a> <ul id="toc-150-foot_Solar_Tower-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-60-inch_telescope" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#60-inch_telescope"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>60-inch telescope</span> </div> </a> <ul id="toc-60-inch_telescope-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-100-inch_Hooker_telescope" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#100-inch_Hooker_telescope"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>100-inch Hooker telescope</span> </div> </a> <button aria-controls="toc-100-inch_Hooker_telescope-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 100-inch Hooker telescope subsection</span> </button> <ul id="toc-100-inch_Hooker_telescope-sublist" class="vector-toc-list"> <li id="toc-Construction" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Construction"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Construction</span> </div> </a> <ul id="toc-Construction-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Interferometry" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Interferometry"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Interferometry</span> </div> </a> <button aria-controls="toc-Interferometry-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 Interferometry subsection</span> </button> <ul id="toc-Interferometry-sublist" class="vector-toc-list"> <li id="toc-20-foot_Stellar_Interferometer" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#20-foot_Stellar_Interferometer"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.1</span> <span>20-foot Stellar Interferometer</span> </div> </a> <ul id="toc-20-foot_Stellar_Interferometer-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-50-foot_Stellar_Interferometer" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#50-foot_Stellar_Interferometer"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2</span> <span>50-foot Stellar Interferometer</span> </div> </a> <ul id="toc-50-foot_Stellar_Interferometer-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Infrared_Spatial_Interferometer" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Infrared_Spatial_Interferometer"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.3</span> <span>Infrared Spatial Interferometer</span> </div> </a> <ul id="toc-Infrared_Spatial_Interferometer-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-CHARA_array" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#CHARA_array"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.4</span> <span>CHARA array</span> </div> </a> <ul id="toc-CHARA_array-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Other_telescopes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Other_telescopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Other telescopes</span> </div> </a> <ul id="toc-Other_telescopes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Events" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Events"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Events</span> </div> </a> <ul id="toc-Events-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Sunday_Afternoon_Concerts_in_the_Dome" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Sunday_Afternoon_Concerts_in_the_Dome"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Sunday Afternoon Concerts in the Dome</span> </div> </a> <ul id="toc-Sunday_Afternoon_Concerts_in_the_Dome-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-In_popular_culture" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#In_popular_culture"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>In popular culture</span> </div> </a> <ul id="toc-In_popular_culture-sublist" class="vector-toc-list"> </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">9</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">10</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">11</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">Mount Wilson Observatory</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 46 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-46" 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">46 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%85%D8%B1%D8%B5%D8%AF_%D8%AC%D8%A8%D9%84_%D9%88%D9%8A%D9%84%D8%B3%D9%88%D9%86" title="مرصد جبل ويلسون – Arabic" lang="ar" hreflang="ar" data-title="مرصد جبل ويلسون" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/Observatoriu_del_Monte_Wilson" title="Observatoriu del Monte Wilson – Asturian" lang="ast" hreflang="ast" data-title="Observatoriu del Monte Wilson" data-language-autonym="Asturianu" data-language-local-name="Asturian" class="interlanguage-link-target"><span>Asturianu</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Observatori_de_Mount_Wilson" title="Observatori de Mount Wilson – Catalan" lang="ca" hreflang="ca" data-title="Observatori de Mount Wilson" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Observato%C5%99_Mount_Wilson" title="Observatoř Mount Wilson – Czech" lang="cs" hreflang="cs" data-title="Observatoř Mount Wilson" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-cy mw-list-item"><a href="https://cy.wikipedia.org/wiki/Arsyllfa_Mount_Wilson" title="Arsyllfa Mount Wilson – Welsh" lang="cy" hreflang="cy" data-title="Arsyllfa Mount Wilson" 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/Mount_Wilson_Observatory" title="Mount Wilson Observatory – Danish" lang="da" hreflang="da" data-title="Mount Wilson Observatory" 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/Mount-Wilson-Observatorium" title="Mount-Wilson-Observatorium – German" lang="de" hreflang="de" data-title="Mount-Wilson-Observatorium" 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/Mount_Wilsoni_observatoorium" title="Mount Wilsoni observatoorium – Estonian" lang="et" hreflang="et" data-title="Mount Wilsoni observatoorium" 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%91%CF%83%CF%84%CE%B5%CF%81%CE%BF%CF%83%CE%BA%CE%BF%CF%80%CE%B5%CE%AF%CE%BF_%CF%84%CE%BF%CF%85_%CF%8C%CF%81%CE%BF%CF%85%CF%82_%CE%93%CE%BF%CF%85%CE%AF%CE%BB%CF%83%CE%BF%CE%BD" title="Αστεροσκοπείο του όρους Γουίλσον – Greek" lang="el" hreflang="el" data-title="Αστεροσκοπείο του όρους Γουίλσον" 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/Observatorio_del_Monte_Wilson" title="Observatorio del Monte Wilson – Spanish" lang="es" hreflang="es" data-title="Observatorio del Monte Wilson" 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/Observatorio_de_Monto_Wilson" title="Observatorio de Monto Wilson – Esperanto" lang="eo" hreflang="eo" data-title="Observatorio de Monto Wilson" 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/Mount_Wilson_behatokia" title="Mount Wilson behatokia – Basque" lang="eu" hreflang="eu" data-title="Mount Wilson behatokia" 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%B1%D8%B5%D8%AF%D8%AE%D8%A7%D9%86%D9%87_%D9%85%D9%88%D9%86%D8%AA%E2%80%8C%D9%88%DB%8C%D9%84%D8%B3%D9%88%D9%86" title="رصدخانه مونت‌ویلسون – Persian" lang="fa" hreflang="fa" data-title="رصدخانه مونت‌ویلسون" 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/Observatoire_du_Mont_Wilson" title="Observatoire du Mont Wilson – French" lang="fr" hreflang="fr" data-title="Observatoire du Mont Wilson" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%9C%8C%EC%8A%A8%EC%82%B0_%EC%B2%9C%EB%AC%B8%EB%8C%80" title="윌슨산 천문대 – Korean" lang="ko" hreflang="ko" data-title="윌슨산 천문대" 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%A1%D5%B8%D6%82%D5%B6%D5%A9_%D5%8E%D5%AB%D5%AC%D5%BD%D5%B8%D5%B6%D5%AB_%D5%A1%D5%BD%D5%BF%D5%B2%D5%A1%D5%A4%D5%AB%D5%BF%D5%A1%D6%80%D5%A1%D5%B6" title="Մաունթ Վիլսոնի աստղադիտարան – Armenian" lang="hy" hreflang="hy" data-title="Մաունթ Վիլսոնի աստղադիտարան" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Observatorium_Mount_Wilson" title="Observatorium Mount Wilson – Indonesian" lang="id" hreflang="id" data-title="Observatorium Mount Wilson" 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-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Osservatorio_di_Monte_Wilson" title="Osservatorio di Monte Wilson – Italian" lang="it" hreflang="it" data-title="Osservatorio di Monte Wilson" 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%9E%D7%A6%D7%A4%D7%94_%D7%94%D7%A8_%D7%95%D7%99%D7%9C%D7%A1%D7%95%D7%9F" title="מצפה הר וילסון – Hebrew" lang="he" hreflang="he" data-title="מצפה הר וילסון" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/%E1%83%9B%E1%83%90%E1%83%A3%E1%83%9C%E1%83%A2-%E1%83%A3%E1%83%98%E1%83%9A%E1%83%A1%E1%83%9D%E1%83%9C%E1%83%98%E1%83%A1_%E1%83%9D%E1%83%91%E1%83%A1%E1%83%94%E1%83%A0%E1%83%95%E1%83%90%E1%83%A2%E1%83%9D%E1%83%A0%E1%83%98%E1%83%90" title="მაუნტ-უილსონის ობსერვატორია – Georgian" lang="ka" hreflang="ka" data-title="მაუნტ-უილსონის ობსერვატორია" data-language-autonym="ქართული" data-language-local-name="Georgian" class="interlanguage-link-target"><span>ქართული</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Observatorium_Montis_Wilson" title="Observatorium Montis Wilson – Latin" lang="la" hreflang="la" data-title="Observatorium Montis Wilson" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-lb mw-list-item"><a href="https://lb.wikipedia.org/wiki/Mount_Wilson-Observatoire" title="Mount Wilson-Observatoire – Luxembourgish" lang="lb" hreflang="lb" data-title="Mount Wilson-Observatoire" 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/Maunt_Vilsonas" title="Maunt Vilsonas – Lithuanian" lang="lt" hreflang="lt" data-title="Maunt Vilsonas" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Wilson-hegyi_Obszervat%C3%B3rium" title="Wilson-hegyi Obszervatórium – Hungarian" lang="hu" hreflang="hu" data-title="Wilson-hegyi Obszervatórium" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%AE%E0%B5%97%E0%B4%A3%E0%B5%8D%E0%B4%9F%E0%B5%8D_%E0%B4%B5%E0%B4%BF%E0%B5%BD%E0%B4%B8%E0%B5%BA_%E0%B4%92%E0%B4%AC%E0%B5%8D%E0%B4%B8%E0%B5%BC%E0%B4%B5%E0%B5%87%E0%B4%B1%E0%B5%8D%E0%B4%B1%E0%B4%B1%E0%B4%BF" title="മൗണ്ട് വിൽസൺ ഒബ്സർവേറ്ററി – Malayalam" lang="ml" hreflang="ml" data-title="മൗണ്ട് വിൽസൺ ഒബ്സർവേറ്ററി" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-xmf mw-list-item"><a href="https://xmf.wikipedia.org/wiki/%E1%83%9B%E1%83%90%E1%83%A3%E1%83%9C%E1%83%97-%E1%83%95%E1%83%98%E1%83%9A%E1%83%A1%E1%83%9D%E1%83%9C%E1%83%98%E1%83%A8_%E1%83%9D%E1%83%91%E1%83%A1%E1%83%94%E1%83%A0%E1%83%95%E1%83%90%E1%83%A2%E1%83%9D%E1%83%A0%E1%83%98%E1%83%90" title="მაუნთ-ვილსონიშ ობსერვატორია – Mingrelian" lang="xmf" hreflang="xmf" data-title="მაუნთ-ვილსონიშ ობსერვატორია" 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%85%D8%B1%D8%B5%D8%AF_%D8%AC%D8%A8%D9%84_%D9%88%D9%8A%D9%84%D8%B3%D9%88%D9%86" title="مرصد جبل ويلسون – Egyptian Arabic" lang="arz" hreflang="arz" data-title="مرصد جبل ويلسون" data-language-autonym="مصرى" data-language-local-name="Egyptian Arabic" class="interlanguage-link-target"><span>مصرى</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Mount_Wilson-observatorium" title="Mount Wilson-observatorium – Dutch" lang="nl" hreflang="nl" data-title="Mount Wilson-observatorium" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E3%82%A6%E3%82%A3%E3%83%AB%E3%82%BD%E3%83%B3%E5%B1%B1%E5%A4%A9%E6%96%87%E5%8F%B0" title="ウィルソン山天文台 – Japanese" lang="ja" hreflang="ja" data-title="ウィルソン山天文台" 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-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Mount_Wilson_Observatory" title="Mount Wilson Observatory – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Mount Wilson Observatory" 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/Mount_Wilson-observatoriet" title="Mount Wilson-observatoriet – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Mount Wilson-observatoriet" 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-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Mount_Wilson_astronomik_rasadxonasi" title="Mount Wilson astronomik rasadxonasi – Uzbek" lang="uz" hreflang="uz" data-title="Mount Wilson astronomik rasadxonasi" 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-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Mount_Wilson_Observatory" title="Mount Wilson Observatory – Polish" lang="pl" hreflang="pl" data-title="Mount Wilson Observatory" 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/Observat%C3%B3rio_Monte_Wilson" title="Observatório Monte Wilson – Portuguese" lang="pt" hreflang="pt" data-title="Observatório Monte Wilson" 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/Observatorul_Mont_Wilson" title="Observatorul Mont Wilson – Romanian" lang="ro" hreflang="ro" data-title="Observatorul Mont Wilson" 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%9C%D0%B0%D1%83%D0%BD%D1%82-%D0%92%D0%B8%D0%BB%D1%81%D0%BE%D0%BD" title="Маунт-Вилсон – Russian" lang="ru" hreflang="ru" data-title="Маунт-Вилсон" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-ckb mw-list-item"><a href="https://ckb.wikipedia.org/wiki/%DA%95%D9%88%D8%A7%D9%86%DA%AF%DB%95%DB%8C_%DA%86%DB%8C%D8%A7%DB%8C_%D9%88%DB%8C%DA%B5%D8%B3%DB%86%D9%86" title="ڕوانگەی چیای ویڵسۆن – Central Kurdish" lang="ckb" hreflang="ckb" data-title="ڕوانگەی چیای ویڵسۆن" 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/Opservatorija_Maunt_Vilson" title="Opservatorija Maunt Vilson – Serbian" lang="sr" hreflang="sr" data-title="Opservatorija Maunt Vilson" 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-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Mount_Wilsonin_observatorio" title="Mount Wilsonin observatorio – Finnish" lang="fi" hreflang="fi" data-title="Mount Wilsonin observatorio" 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/Mount_Wilson-observatoriet" title="Mount Wilson-observatoriet – Swedish" lang="sv" hreflang="sv" data-title="Mount Wilson-observatoriet" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Wilson_Da%C4%9F%C4%B1_G%C3%B6zlemevi" title="Wilson Dağı Gözlemevi – Turkish" lang="tr" hreflang="tr" data-title="Wilson Dağı Gözlemevi" 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%9E%D0%B1%D1%81%D0%B5%D1%80%D0%B2%D0%B0%D1%82%D0%BE%D1%80%D1%96%D1%8F_%D0%9C%D0%B0%D1%83%D0%BD%D1%82-%D0%92%D1%96%D0%BB%D1%81%D0%BE%D0%BD" title="Обсерваторія Маунт-Вілсон – Ukrainian" lang="uk" hreflang="uk" data-title="Обсерваторія Маунт-Вілсон" 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/%D9%85%D8%A7%D8%A4%D9%86%D9%B9_%D9%88%D9%84%D8%B3%D9%86%D8%8C_%DA%A9%DB%8C%D9%84%DB%8C%D9%81%D9%88%D8%B1%D9%86%DB%8C%D8%A7" title="ماؤنٹ ولسن، کیلیفورنیا – Urdu" lang="ur" hreflang="ur" data-title="ماؤنٹ ولسن، کیلیفورنیا" data-language-autonym="اردو" data-language-local-name="Urdu" class="interlanguage-link-target"><span>اردو</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/%C4%90%C3%A0i_thi%C3%AAn_v%C4%83n_N%C3%BAi_Wilson" title="Đài thiên văn Núi Wilson – Vietnamese" lang="vi" hreflang="vi" data-title="Đài thiên văn Núi Wilson" 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-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%E5%A8%81%E7%88%BE%E9%81%9C%E5%B1%B1%E5%A4%A9%E6%96%87%E5%8F%B0" title="威爾遜山天文台 – Cantonese" lang="yue" hreflang="yue" data-title="威爾遜山天文台" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target"><span>粵語</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%A8%81%E5%B0%94%E9%80%8A%E5%B1%B1%E5%A4%A9%E6%96%87%E5%8F%B0" title="威尔逊山天文台 – Chinese" lang="zh" hreflang="zh" data-title="威尔逊山天文台" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q466863#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Mount_Wilson_Observatory" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:Mount_Wilson_Observatory" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Mount_Wilson_Observatory"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Mount_Wilson_Observatory&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Mount_Wilson_Observatory"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Mount_Wilson_Observatory&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/Mount_Wilson_Observatory" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/Mount_Wilson_Observatory" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Mount_Wilson_Observatory&oldid=1269285229" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Mount_Wilson_Observatory&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=Mount_Wilson_Observatory&id=1269285229&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FMount_Wilson_Observatory"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FMount_Wilson_Observatory"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=Mount_Wilson_Observatory&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Mount_Wilson_Observatory&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="wb-otherproject-link wb-otherproject-commons mw-list-item"><a href="https://commons.wikimedia.org/wiki/Category:Mount_Wilson_Observatory" hreflang="en"><span>Wikimedia Commons</span></a></li><li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q466863" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </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 id="mw-indicator-coordinates" class="mw-indicator"><div class="mw-parser-output"><span id="coordinates"><a href="/wiki/Geographic_coordinate_system" title="Geographic coordinate system">Coordinates</a>: <style data-mw-deduplicate="TemplateStyles:r1156832818">.mw-parser-output .geo-default,.mw-parser-output .geo-dms,.mw-parser-output .geo-dec{display:inline}.mw-parser-output .geo-nondefault,.mw-parser-output .geo-multi-punct,.mw-parser-output .geo-inline-hidden{display:none}.mw-parser-output .longitude,.mw-parser-output .latitude{white-space:nowrap}</style><span class="plainlinks nourlexpansion"><a class="external text" href="https://geohack.toolforge.org/geohack.php?pagename=Mount_Wilson_Observatory&params=34.22503_N_118.05719_W_"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">34°13′30″N</span> <span class="longitude">118°03′26″W</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">34.22503°N 118.05719°W</span><span style="display:none"> / <span class="geo">34.22503; -118.05719</span></span></span></a></span></span></div></div> </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">Astronomical observatory in Los Angeles County, California, USA</div> <p><span class="anchor" id="top-of-lead"></span> </p> <div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Observatory</div><style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox vcard"><caption class="infobox-title fn org">Mount Wilson Observatory</caption><tbody><tr><td colspan="2" class="infobox-image"><span class="mw-default-size" typeof="mw:File/Frameless"><a href="/wiki/File:Chara-2000-09-15.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/20/Chara-2000-09-15.JPG/290px-Chara-2000-09-15.JPG" decoding="async" width="290" height="218" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/20/Chara-2000-09-15.JPG/435px-Chara-2000-09-15.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/20/Chara-2000-09-15.JPG/580px-Chara-2000-09-15.JPG 2x" data-file-width="1280" data-file-height="960" /></a></span><div class="infobox-caption">Looking down on the top of Mount Wilson, including the historic 100" <a href="/wiki/Hooker_telescope" class="mw-redirect" title="Hooker telescope">Hooker telescope</a> (center), the 60" telescope (center left), and the CHARA array</div></td></tr><tr><th scope="row" class="infobox-label">Alternative names</th><td class="infobox-data">672 MW <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q466863" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Organization</th><td class="infobox-data"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style><div class="plainlist"><ul><li><a href="/wiki/Carnegie_Institution_for_Science" title="Carnegie Institution for Science">Carnegie Institution for Science</a> <span class="penicon autoconfirmed-show"><span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q466863?uselang=en#P137" title="Edit this on Wikidata"><img alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></li></ul></div></td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/List_of_observatory_codes" title="List of observatory codes">Observatory code</a></th><td class="infobox-data"><a href="/wiki/List_of_observatory_codes#672" title="List of observatory codes"> 672</a> <span class="penicon autoconfirmed-show"><span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q466863?uselang=en#P717" title="Edit this on Wikidata"><img alt="Edit this on Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></span></td></tr><tr><th scope="row" class="infobox-label">Location</th><td class="infobox-data"><a href="/wiki/Mount_Wilson_(California)" title="Mount Wilson (California)">Mount Wilson</a>, California, US</td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Geographic_coordinate_system" title="Geographic coordinate system">Coordinates</a></th><td class="infobox-data"><span class="geo-inline"><style data-mw-deduplicate="TemplateStyles:r1156832818">.mw-parser-output .geo-default,.mw-parser-output .geo-dms,.mw-parser-output .geo-dec{display:inline}.mw-parser-output .geo-nondefault,.mw-parser-output .geo-multi-punct,.mw-parser-output .geo-inline-hidden{display:none}.mw-parser-output .longitude,.mw-parser-output .latitude{white-space:nowrap}</style><span class="plainlinks nourlexpansion"><a class="external text" href="https://geohack.toolforge.org/geohack.php?pagename=Mount_Wilson_Observatory&params=34.22503_N_118.05719_W_"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">34°13′30″N</span> <span class="longitude">118°03′26″W</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">34.22503°N 118.05719°W</span><span style="display:none"> / <span class="geo">34.22503; -118.05719</span></span></span></a></span></span></td></tr><tr><th scope="row" class="infobox-label">Altitude</th><td class="infobox-data">1,742 m (5,715 ft) <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q466863#P2044" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th scope="row" class="infobox-label">Website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="https://www.mtwilson.edu">www<wbr />.mtwilson<wbr />.edu</a></span> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q466863#P856" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></td></tr><tr><th colspan="2" class="infobox-header">Telescopes</th></tr><tr><td colspan="2" class="infobox-full-data"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1257001546"><table class="infobox-subbox"><tbody><tr><th scope="row" class="infobox-label"><a href="#60-inch_telescope">60-inch telescope</a></th><td class="infobox-data">1.5-meter (60 in) reflector</td></tr><tr><th scope="row" class="infobox-label"><a href="#100-inch_Hooker_telescope">Hooker telescope</a></th><td class="infobox-data">2.5-meter (100 in) reflector</td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Infrared_Spatial_Interferometer" title="Infrared Spatial Interferometer">Infrared Spatial Interferometer</a></th><td class="infobox-data">3 × 1.7-meter (65 in) reflectors</td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/CHARA_array" title="CHARA array">CHARA array</a></th><td class="infobox-data">6 × 1-meter (40 in) reflectors</td></tr></tbody></table></td></tr><tr><td colspan="2" class="infobox-full-data"><style data-mw-deduplicate="TemplateStyles:r1238443738">.mw-parser-output .locmap .od{position:absolute}.mw-parser-output .locmap .id{position:absolute;line-height:0}.mw-parser-output .locmap .l0{font-size:0;position:absolute}.mw-parser-output .locmap .pv{line-height:110%;position:absolute;text-align:center}.mw-parser-output .locmap .pl{line-height:110%;position:absolute;top:-0.75em;text-align:right}.mw-parser-output .locmap .pr{line-height:110%;position:absolute;top:-0.75em;text-align:left}.mw-parser-output .locmap .pv>div{display:inline;padding:1px}.mw-parser-output .locmap .pl>div{display:inline;padding:1px;float:right}.mw-parser-output .locmap .pr>div{display:inline;padding:1px;float:left}@media screen{html.skin-theme-clientpref-night .mw-parser-output .od,html.skin-theme-clientpref-night .mw-parser-output .od .pv>div,html.skin-theme-clientpref-night .mw-parser-output .od .pl>div,html.skin-theme-clientpref-night .mw-parser-output .od .pr>div{background:#fff!important;color:#000!important}html.skin-theme-clientpref-night .mw-parser-output .locmap{filter:grayscale(0.6)}html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data .locmap div{background:transparent!important}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .locmap{filter:grayscale(0.6)}html.skin-theme-clientpref-os .mw-parser-output .od,html.skin-theme-clientpref-os .mw-parser-output .od .pv>div,html.skin-theme-clientpref-os .mw-parser-output .od .pl>div,html.skin-theme-clientpref-os .mw-parser-output .od .pr>div{background:white!important;color:#000!important}html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data .locmap div{background:transparent!important}}</style><div class="center"><div class="locmap" style="width:240px;float:none;clear:both;margin-left:auto;margin-right:auto"><div style="width:240px;padding:0"><div style="position:relative;width:240px"><span class="notpageimage" typeof="mw:File"><a href="/wiki/File:Usa_edcp_relief_location_map.png" class="mw-file-description" title="Mount Wilson Observatory is located in the United States"><img alt="Mount Wilson Observatory is located in the United States" src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f3/Usa_edcp_relief_location_map.png/240px-Usa_edcp_relief_location_map.png" decoding="async" width="240" height="149" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f3/Usa_edcp_relief_location_map.png/360px-Usa_edcp_relief_location_map.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f3/Usa_edcp_relief_location_map.png/480px-Usa_edcp_relief_location_map.png 2x" data-file-width="1181" data-file-height="731" /></a></span><div class="od notheme" style="top:57.614%;left:10.972%;font-size:91%"><div class="id" style="left:-4px;top:-4px"><span class="notpageimage" typeof="mw:File"><span title="Mount Wilson Observatory"><img alt="Mount Wilson Observatory" src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Red_pog.svg/8px-Red_pog.svg.png" decoding="async" width="8" height="8" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Red_pog.svg/12px-Red_pog.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Red_pog.svg/16px-Red_pog.svg.png 2x" data-file-width="64" data-file-height="64" /></span></span></div></div></div><div style="padding-top:0.2em"><div style="line-height:1.2em;">Location of Mount Wilson Observatory</div></div></div></div></div></td></tr><tr><td colspan="2" class="infobox-full-data"> <span class="noviewer" typeof="mw:File"><a href="/wiki/File:Commons-logo.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></span> <a href="https://commons.wikimedia.org/wiki/Category:Mount_Wilson_Observatory" class="extiw" title="commons:Category:Mount Wilson Observatory">Related media on Commons</a></td></tr><tr><td colspan="2" class="infobox-below"><div class="metadata" style="text-align: right;">[<a href="https://www.wikidata.org/wiki/Q466863" class="extiw" title="d:Q466863">edit on Wikidata</a>]</div></td></tr></tbody></table> <p>The <b>Mount Wilson Observatory</b> (<b>MWO</b>) is an <a href="/wiki/Observatory#Astronomical_observatories" title="Observatory">astronomical observatory</a> in <a href="/wiki/Los_Angeles_County,_California" title="Los Angeles County, California">Los Angeles County, California</a>, United States. The MWO is located on <a href="/wiki/Mount_Wilson_(California)" title="Mount Wilson (California)">Mount Wilson</a>, a 5,710-foot (1,740-meter) peak in the <a href="/wiki/San_Gabriel_Mountains" title="San Gabriel Mountains">San Gabriel Mountains</a> near <a href="/wiki/Pasadena,_California" title="Pasadena, California">Pasadena</a>, northeast of Los Angeles. </p><p>The observatory contains two historically important telescopes: the 100-inch (2.5 m) <a href="#100-inch_Hooker_telescope">Hooker telescope</a>, which was the largest aperture telescope in the world from its completion in 1917 to 1949, and the <a href="#60-inch_telescope">60-inch telescope</a> which was the largest operational telescope in the world when it was completed in 1908. It also contains the <a href="/wiki/Snow_solar_telescope" class="mw-redirect" title="Snow solar telescope">Snow solar telescope</a> completed in 1905, the 60-foot (18 m) solar tower completed in 1908, the 150-foot (46 m) solar tower completed in 1912, and the <a href="/wiki/CHARA_array" title="CHARA array">CHARA array</a>, built by <a href="/wiki/Georgia_State_University" title="Georgia State University">Georgia State University</a>, which became fully operational in 2004 and was the largest optical interferometer in the world at its completion. </p><p>Due to the <a href="/wiki/Inversion_(meteorology)" title="Inversion (meteorology)">inversion layer</a> that traps warm air and <a href="/wiki/Smog" title="Smog">smog</a> over Los Angeles, Mount Wilson has steadier air than any other location in North America, making it ideal for astronomy and in particular for <a href="/wiki/Interferometry" title="Interferometry">interferometry</a>.<sup id="cite_ref-lat_1-0" class="reference"><a href="#cite_note-lat-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> The increasing <a href="/wiki/Light_pollution" title="Light pollution">light pollution</a> due to the growth of greater Los Angeles has limited the ability of the observatory to engage in deep space astronomy, but it remains a productive center, with the CHARA array continuing important stellar research. </p><p>The initial efforts to mount a telescope to Mount Wilson occurred in the 1880s by one of the founders of <a href="/wiki/University_of_Southern_California" title="University of Southern California">University of Southern California</a>, <a href="/wiki/Edward_Falles_Spence" title="Edward Falles Spence">Edward Falles Spence</a>, but he died without finishing the funding effort.<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> The observatory was conceived and founded by <a href="/wiki/George_Ellery_Hale" title="George Ellery Hale">George Ellery Hale</a>, who had previously built the 1 meter telescope at the <a href="/wiki/Yerkes_Observatory" title="Yerkes Observatory">Yerkes Observatory</a>, then the world's largest telescope. The Mount Wilson Solar Observatory was first funded by the <a href="/wiki/Carnegie_Institution_of_Washington" class="mw-redirect" title="Carnegie Institution of Washington">Carnegie Institution of Washington</a> in 1904, leasing the land from the owners of the Mount Wilson Hotel in 1904. Among the conditions of the lease was that it allow public access.<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> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Solar_telescopes">Solar telescopes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=1" title="Edit section: Solar telescopes"><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:The_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson_as_seen_from_near_the_base.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fc/The_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson_as_seen_from_near_the_base.jpg/170px-The_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson_as_seen_from_near_the_base.jpg" decoding="async" width="170" height="264" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fc/The_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson_as_seen_from_near_the_base.jpg/255px-The_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson_as_seen_from_near_the_base.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fc/The_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson_as_seen_from_near_the_base.jpg/340px-The_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson_as_seen_from_near_the_base.jpg 2x" data-file-width="2160" data-file-height="3351" /></a><figcaption>At the base of the 150-foot Solar Tower.</figcaption></figure> <p>There are three <a href="/wiki/Solar_telescope" title="Solar telescope">solar telescopes</a> at Mount Wilson Observatory. Just one of these telescopes, the 60-foot Solar Tower, is still used for solar research. </p> <div class="mw-heading mw-heading3"><h3 id="Snow_Solar_Telescope">Snow Solar Telescope</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=2" title="Edit section: Snow Solar Telescope"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The Snow Solar Telescope was the first telescope installed at the fledgling Mount Wilson Solar Observatory. It was the world's first permanently mounted solar telescope. Solar telescopes had previously been portable so they could be taken to solar eclipses around the world. The telescope was donated to Yerkes Observatory by Helen Snow of Chicago. George Ellery Hale, then director of Yerkes, had the telescope brought to Mount Wilson to put it into service as a proper scientific instrument. Its 24-inch (61 cm) primary mirror with a 60-foot (18 m) focal length, coupled with a spectrograph, did groundbreaking work on the spectra of sunspots, doppler shift of the rotating solar disc and daily solar images in several wavelengths. Stellar research soon followed as the brightest stars could have their spectra recorded with very long exposures on glass plates.<sup id="cite_ref-mtwilson.edu_4-0" class="reference"><a href="#cite_note-mtwilson.edu-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> The Snow solar telescope is mostly used by undergraduate students who get hands-on training in solar physics and spectroscopy.<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> It was also used publicly for the May 9, 2016 transit of Mercury across the face of the Sun. </p> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:The_top_of_the_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/52/The_top_of_the_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson.jpg/220px-The_top_of_the_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson.jpg" decoding="async" width="220" height="208" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/52/The_top_of_the_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson.jpg/330px-The_top_of_the_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/52/The_top_of_the_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson.jpg/440px-The_top_of_the_150-Foot_Solar_Tower_Observatory_on_Mt._Wilson.jpg 2x" data-file-width="2194" data-file-height="2072" /></a><figcaption>Top of the Solar tower containing the mirrors</figcaption></figure> <div class="mw-heading mw-heading3"><h3 id="60-foot_Solar_Tower">60-foot Solar Tower</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=3" title="Edit section: 60-foot Solar Tower"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The 60-foot (18 m) Solar Tower soon built on the work started at the Snow telescope. At its completion in 1908, the vertical tower design of the 60-foot focal length solar telescope allowed much higher resolution of the solar image and spectrum than the Snow telescope could achieve. The higher resolution came from situating the optics higher above the ground, thereby avoiding the distortion caused by the heating of the ground by the Sun. On June 25, 1908, Hale would record <a href="/wiki/Zeeman_splitting" class="mw-redirect" title="Zeeman splitting">Zeeman splitting</a> in the spectrum of a sunspot, showing for the first time that magnetic fields existed somewhere besides the Earth. A later discovery was of the reversed polarity in sunspots of the new solar cycle of 1912. The success of the 60-foot Tower prompted Hale to pursue yet another, taller tower telescope. In the 1960s, Robert Leighton discovered the Sun had a 5-minute oscillation and the field of helioseismology was born.<sup id="cite_ref-mtwilson.edu_4-1" class="reference"><a href="#cite_note-mtwilson.edu-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup><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 60-foot Tower is operated by the Department of Physics and Astronomy at <a href="/wiki/University_of_Southern_California" title="University of Southern California">University of Southern California</a>. </p> <div class="mw-heading mw-heading3"><h3 id="150-foot_Solar_Tower">150-foot Solar Tower</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=4" title="Edit section: 150-foot Solar Tower"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The 150-foot (46 m) focal length solar tower expanded on the solar tower design with its tower-in-a-tower design. (The tower is actually 176 feet (54 m) tall.) An inner tower supports the optics above, while an outer tower, which completely surrounds the inner tower, supports the dome and floors around the optics. This design allowed complete isolation of the optics from the effect of wind swaying the tower. Two mirrors feed sunlight to a 12-inch (30 cm) lens which focuses light down at the ground floor. It was first completed in 1910, but unsatisfactory optics caused a two-year delay before a suitable doublet lens was installed. Research included solar rotation, sunspot polarities, daily <a href="/wiki/Sunspot_drawing" title="Sunspot drawing">sunspot drawings</a>, and many magnetic field studies. The solar telescope would be the world's largest for 50 years until the McMath-Pierce Solar telescope was completed at <a href="/wiki/Kitt_Peak" title="Kitt Peak">Kitt Peak</a> in Arizona in 1962. In 1985, UCLA took over operation of the solar tower from the Carnegie Observatories after they decided to stop funding the observatory.<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> </p> <div class="mw-heading mw-heading2"><h2 id="60-inch_telescope">60-inch telescope</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=5" title="Edit section: 60-inch telescope"><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:60-inch_Telescope.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/29/60-inch_Telescope.JPG/170px-60-inch_Telescope.JPG" decoding="async" width="170" height="284" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/29/60-inch_Telescope.JPG/255px-60-inch_Telescope.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/29/60-inch_Telescope.JPG/340px-60-inch_Telescope.JPG 2x" data-file-width="2546" data-file-height="4256" /></a><figcaption>The 60-inch (1.5 m) telescope at Mt. Wilson</figcaption></figure> <p>For the 60-inch telescope, <a href="/wiki/George_Ellery_Hale" title="George Ellery Hale">George Ellery Hale</a> received the 60-inch (1.5 m) mirror blank, cast by <a href="/wiki/Saint-Gobain" title="Saint-Gobain">Saint-Gobain</a> in France, in 1896 as a gift from his father, William Hale. It was a glass disk 19 cm thick and weighing 860 kg. However it was not until 1904 that Hale received funding from the Carnegie Institution to build an observatory. Grinding began in 1905 and took two years. The mounting and structure for the telescope were built in <a href="/wiki/San_Francisco" title="San Francisco">San Francisco</a> and barely survived the <a href="/wiki/1906_San_Francisco_earthquake" title="1906 San Francisco earthquake">1906 earthquake</a>. Transporting the pieces to the top of Mount Wilson was an enormous task. <a href="/wiki/First_light_(astronomy)" title="First light (astronomy)">First light</a> was December 8, 1908. It was, at the time, the largest operational telescope in the world.<sup id="cite_ref-lat_1-1" class="reference"><a href="#cite_note-lat-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> Lord Rosse's <a href="/wiki/Leviathan_of_Parsonstown" title="Leviathan of Parsonstown">Leviathan of Parsonstown</a>, a 72-inch (1.8-meter) telescope built in 1845, was, by the 1890s, out of commission. </p><p>Although slightly smaller than the Leviathan, the 60-inch had many advantages including a far better site, a glass mirror instead of speculum metal, and a precision mount which could accurately track any direction in the sky, so the 60-inch was a major advance. </p> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:Voyage_in_Space_page097.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Voyage_in_Space_page097.jpg/220px-Voyage_in_Space_page097.jpg" decoding="async" width="220" height="173" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Voyage_in_Space_page097.jpg/330px-Voyage_in_Space_page097.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Voyage_in_Space_page097.jpg/440px-Voyage_in_Space_page097.jpg 2x" data-file-width="1793" data-file-height="1413" /></a><figcaption>Five-foot telescope being transported up the mountain</figcaption></figure> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:PSM_V74_D518_Steel_building_and_60_inch_reflector.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e9/PSM_V74_D518_Steel_building_and_60_inch_reflector.png/220px-PSM_V74_D518_Steel_building_and_60_inch_reflector.png" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e9/PSM_V74_D518_Steel_building_and_60_inch_reflector.png/330px-PSM_V74_D518_Steel_building_and_60_inch_reflector.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e9/PSM_V74_D518_Steel_building_and_60_inch_reflector.png/440px-PSM_V74_D518_Steel_building_and_60_inch_reflector.png 2x" data-file-width="1568" data-file-height="1050" /></a><figcaption>Steel dome of the 60-inch telescope in 1909</figcaption></figure> <p>The 60-inch telescope is a reflector telescope built for <a href="/wiki/Newtonian_telescope" title="Newtonian telescope">Newtonian</a>, <a href="/wiki/Cassegrain_reflector" title="Cassegrain reflector">Cassegrain</a> and <a href="/wiki/Coud%C3%A9_focus" class="mw-redirect" title="Coudé focus">coudé</a> configurations. It is currently used in the bent Cassegrain configuration. It became one of the most productive and successful telescopes in astronomical history. Its design and light-gathering power allowed the pioneering of <a href="/wiki/Spectroscopic" class="mw-redirect" title="Spectroscopic">spectroscopic</a> analysis, <a href="/wiki/Parallax" title="Parallax">parallax</a> measurements, <a href="/wiki/Nebula" title="Nebula">nebula</a> photography, and <a href="/wiki/Photometry_(astronomy)" title="Photometry (astronomy)">photometric</a> photography.<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> Though surpassed in size by the <a href="#100-inch_Hooker_telescope">§ 100-inch Hooker telescope</a> nine years later, the 60-inch telescope remained one of the largest in use for decades. </p><p>In 1992, the 60-inch telescope was fitted with an early <a href="/wiki/Adaptive_optics" title="Adaptive optics">adaptive optics</a> system, the <i>Atmospheric Compensation Experiment</i> (ACE). The 69-channel system improved the potential resolving power of the telescope from 0.5 to 1.0 arc sec to 0.07 arc sec. ACE was developed by <a href="/wiki/DARPA" title="DARPA">DARPA</a> for the <a href="/wiki/Strategic_Defense_Initiative" title="Strategic Defense Initiative">Strategic Defense Initiative</a> system, and the <a href="/wiki/National_Science_Foundation" title="National Science Foundation">National Science Foundation</a> funded the civilian conversion. </p><p>The telescope is used for public outreach as the second largest telescope in the world devoted to the general public. Custom made 10 cm eyepieces are fitted to its focus using the bent cassegrain configuration to provide views of the Moon, planetary, and deep-sky objects. Groups may book the telescope for an evening of observing.<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> </p> <div class="mw-heading mw-heading2"><h2 id="100-inch_Hooker_telescope"><span class="anchor" id="Hooker_Telescope"></span> 100-inch Hooker telescope</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=6" title="Edit section: 100-inch Hooker telescope"><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:100_inch_Hooker_Telescope_900_px.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/7f/100_inch_Hooker_Telescope_900_px.jpg/220px-100_inch_Hooker_Telescope_900_px.jpg" decoding="async" width="220" height="359" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/7f/100_inch_Hooker_Telescope_900_px.jpg/330px-100_inch_Hooker_Telescope_900_px.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/7f/100_inch_Hooker_Telescope_900_px.jpg/440px-100_inch_Hooker_Telescope_900_px.jpg 2x" data-file-width="1530" data-file-height="2496" /></a><figcaption>The 100-inch Hooker telescope at <a href="#top-of-lead">Mt Wilson</a> fundamentally changed the scientific view of the Universe</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Hooker_Telescope,_Mt_Wilson.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Hooker_Telescope%2C_Mt_Wilson.jpg/220px-Hooker_Telescope%2C_Mt_Wilson.jpg" decoding="async" width="220" height="176" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Hooker_Telescope%2C_Mt_Wilson.jpg/330px-Hooker_Telescope%2C_Mt_Wilson.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Hooker_Telescope%2C_Mt_Wilson.jpg/440px-Hooker_Telescope%2C_Mt_Wilson.jpg 2x" data-file-width="3056" data-file-height="2448" /></a><figcaption>Hooker Telescope enclosure</figcaption></figure> <p>The 100-inch (2.5 m) <b>Hooker telescope</b> located at <a href="#top-of-lead">Mount Wilson Observatory</a>, California, was completed in 1917, and was the <a href="/wiki/List_of_largest_optical_reflecting_telescopes#Chronological_list_of_largest_telescopes" title="List of largest optical reflecting telescopes">world's largest telescope</a> until 1949. It is one of the most famous telescopes in <a href="/wiki/Observational_astronomy" title="Observational astronomy">observational astronomy</a> of the 20th century. It was used by <a href="/wiki/Edwin_Hubble" title="Edwin Hubble">Edwin Hubble</a> to make observations with which he produced two fundamental results which changed the scientific view of the Universe. Using observations he made in 1922–1923, Hubble was <a href="/wiki/Edwin_Hubble#Discoveries" title="Edwin Hubble">able to prove</a> that the Universe extends beyond the Milky Way galaxy, and that several <a href="/wiki/Spiral_galaxy#Spiral_nebula" title="Spiral galaxy">nebulae</a> were millions of light-years away. He then showed that the universe was <a href="/wiki/Expanding_universe" class="mw-redirect" title="Expanding universe">expanding</a>.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> </p> <table class="wikitable" style="max-width: 50em; margin: 0.5em auto;"> <caption>Discoveries made with the Hooker 100-inch telescope: </caption> <tbody><tr> <th width="65">Year</th> <th>Description </th></tr> <tr> <td align="center">1923</td> <td>Edwin Hubble conclusively proves the <a href="/wiki/Great_Andromeda_Nebula" class="mw-redirect" title="Great Andromeda Nebula">Andromeda nebula</a> to be external to the Milky Way galaxy </td></tr> <tr> <td align="center">1929</td> <td>Hubble and <a href="/wiki/Milton_Humason" class="mw-redirect" title="Milton Humason">Milton Humason</a> confirm that the Universe is expanding, measure its expansion rate, and measure the size of the known Universe </td></tr> <tr> <td align="center">1930s</td> <td><a href="/wiki/Fritz_Zwicky" title="Fritz Zwicky">Fritz Zwicky</a> finds evidence for <a href="/wiki/Dark_matter" title="Dark matter">dark matter</a> </td></tr> <tr> <td align="center">1938</td> <td><a href="/wiki/Seth_Barnes_Nicholson" title="Seth Barnes Nicholson">Seth Nickolson</a> finds two satellites of <a href="/wiki/Jupiter" title="Jupiter">Jupiter</a>, referred to as <a href="/wiki/Lysithea_(moon)" title="Lysithea (moon)">#10</a> and <a href="/wiki/Carme_(moon)" title="Carme (moon)">#11</a>.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </td></tr> <tr> <td align="center">1940s</td> <td><a href="/wiki/Walter_Baade" title="Walter Baade">Walter Baade</a>'s observations lead to the distinction of <a href="/wiki/Stellar_population" title="Stellar population">stellar populations</a> and to the discovery of two different types of <a href="/wiki/Cepheid_variable" title="Cepheid variable">Cepheid variable</a> stars, which double the size of the known universe previously calculated by Hubble </td></tr></tbody></table> <div class="mw-heading mw-heading3"><h3 id="Construction">Construction</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=7" title="Edit section: Construction"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:MtWilsonGlass-1917.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/9f/MtWilsonGlass-1917.jpg/220px-MtWilsonGlass-1917.jpg" decoding="async" width="220" height="176" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/9f/MtWilsonGlass-1917.jpg/330px-MtWilsonGlass-1917.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/9f/MtWilsonGlass-1917.jpg/440px-MtWilsonGlass-1917.jpg 2x" data-file-width="750" data-file-height="600" /></a><figcaption>The mirror of the Hooker telescope on its way up the <a href="/wiki/Mount_Wilson_Toll_Road" title="Mount Wilson Toll Road">Mount Wilson Toll Road</a> on a <a href="/wiki/Mack_Truck" class="mw-redirect" title="Mack Truck">Mack Truck</a> in 1917</figcaption></figure> <p>Once the sixty-inch telescope project was well underway, Hale immediately set about creating a larger telescope. <a href="/wiki/John_D._Hooker" class="mw-redirect" title="John D. Hooker">John D. Hooker</a> provided crucial funding of $45,000<sup id="cite_ref-NYT-1907_12-0" class="reference"><a href="#cite_note-NYT-1907-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> for the purchase and grinding of the mirror, while <a href="/wiki/Andrew_Carnegie" title="Andrew Carnegie">Andrew Carnegie</a><sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> provided funds to complete the telescope and dome. The Saint-Gobain factory was again chosen to cast a blank in 1906, which it completed in 1908. After considerable trouble over the blank (and potential replacements), the Hooker telescope was completed and saw "first light" on November 2, 1917. As with the sixty-inch telescope, the bearings are assisted by the use of mercury floats to support the 100 ton weight of the telescope. </p><p>In 1919 the Hooker telescope was equipped with a special attachment, a 6-meter optical <a href="/wiki/Astronomical_interferometer" title="Astronomical interferometer">astronomical interferometer</a> developed by <a href="/wiki/Albert_A._Michelson" title="Albert A. Michelson">Albert A. Michelson</a>, much larger than the one he had used to measure Jupiter's satellites. Michelson was able to use the equipment to determine the precise diameter of stars, such as <a href="/wiki/Betelgeuse" title="Betelgeuse">Betelgeuse</a>, the first time the size of a star had ever been measured. <a href="/wiki/Henry_Norris_Russell" title="Henry Norris Russell">Henry Norris Russell</a> developed his star classification system based on observations using the Hooker. </p><p>In 1935 the silver coating used since 1917 on the Hooker mirror was replaced with a more modern and longer lasting aluminum coating that reflected 50% more light than the older silver coating. The newer method of coating for the telescope mirrors was first tested on the older 1.5 meter mirror.<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> </p> <figure typeof="mw:File/Thumb"><a href="/wiki/File:Assembling_hooker_polar_axis.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a5/Assembling_hooker_polar_axis.jpg/250px-Assembling_hooker_polar_axis.jpg" decoding="async" width="250" height="201" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a5/Assembling_hooker_polar_axis.jpg/375px-Assembling_hooker_polar_axis.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/a/a5/Assembling_hooker_polar_axis.jpg 2x" data-file-width="417" data-file-height="336" /></a><figcaption>Workmen assembling the polar axis of the Hooker telescope</figcaption></figure> <p>Edwin Hubble performed many critical calculations from work on the Hooker telescope. In 1923, Hubble discovered the first <a href="/wiki/Cepheid_variable" title="Cepheid variable">Cepheid variable</a> in the spiral nebula of Andromeda using the 2.5-meter telescope. This discovery allowed him to calculate the distance to the spiral nebula of Andromeda and show that it was actually a <a href="/wiki/Galaxy" title="Galaxy">galaxy</a> outside the <a href="/wiki/Milky_Way" title="Milky Way">Milky Way</a>. Hubble, assisted by <a href="/wiki/Milton_L._Humason" title="Milton L. Humason">Milton L. Humason</a>, observed the magnitude of the <a href="/wiki/Redshift" title="Redshift">redshift</a> in many galaxies and published a paper in 1929 that showed the universe is expanding. </p><p>The Hooker's reign of three decades as the largest telescope came to an end when the <a href="/wiki/Caltech" class="mw-redirect" title="Caltech">Caltech</a>-Carnegie consortium completed its 200-inch (5.1 m) <a href="/wiki/Hale_Telescope" title="Hale Telescope">Hale Telescope</a> at <a href="/wiki/Palomar_Observatory" title="Palomar Observatory">Palomar Observatory</a>, 144 km south, in <a href="/wiki/San_Diego_County,_California" title="San Diego County, California">San Diego County, California</a>. The Hale Telescope saw first light in January 1949.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>By the 1980s, the focus of astronomy research had turned to deep space observation, which required darker skies than what could be found in the Los Angeles area, due to the ever-increasing problem of <a href="/wiki/Light_pollution" title="Light pollution">light pollution</a>. In 1989, the <a href="/wiki/Carnegie_Institution" class="mw-redirect" title="Carnegie Institution">Carnegie Institution</a>, which ran the observatory, handed it over to the non-profit Mount Wilson Institute. At that time, the 2.5-meter telescope was deactivated, but it was restarted in 1992 and in 1995 it was outfitted with a visible light adaptive optics system and later in 1997, it hosted the UnISIS, laser guide star adaptive optics system.<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><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> </p><p>As the use of the telescope for scientific work diminished again, a decision was made to convert it to use for visual observing. Because of the high position of the Cassegrain focus above the observing floor, a system of mirrors and lenses was developed to allow viewing from a position at the bottom of the telescope tube. With the conversion completed in 2014, the 2.5 meter telescope began its new life as the world's largest telescope dedicated to public use. Regularly scheduled observing began with the 2015 observing season.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> </p><p>The telescope has a resolving power of 0.05 <a href="/wiki/Minute_of_arc" class="mw-redirect" title="Minute of arc">arcsecond</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Interferometry">Interferometry</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=8" title="Edit section: Interferometry"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></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">Further information: <a href="/wiki/Astronomical_interferometer" title="Astronomical interferometer">Astronomical interferometer</a> and <a href="/wiki/List_of_astronomical_interferometers_at_visible_and_infrared_wavelengths" title="List of astronomical interferometers at visible and infrared wavelengths">List of astronomical interferometers at visible and infrared wavelengths</a></div> <p><a href="/wiki/Astronomical_interferometry" class="mw-redirect" title="Astronomical interferometry">Astronomical interferometry</a> has a rich history at Mount Wilson. No fewer than seven interferometers have been located here. The reason for this is the extremely steady air over Mount Wilson is well suited to interferometry, the use of multiple viewing points to increase resolution enough to allow for the direct measurement of details such as star diameters. </p> <div class="mw-heading mw-heading3"><h3 id="20-foot_Stellar_Interferometer">20-foot Stellar Interferometer</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=9" title="Edit section: 20-foot Stellar Interferometer"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The first of these interferometers was the 20-foot Stellar Interferometer. In 1919 the 100-inch Hooker telescope was equipped with a special attachment, a 20-foot optical astronomical interferometer developed by Albert A. Michelson and Francis G. Pease. It was attached to the end of the 100-inch telescope and used the telescope as a guiding platform to maintain alignment with the stars being studied. By December 1920, Michelson and Pease were able to use the equipment to determine the precise diameter of a star, the red giant Betelgeuse, the first time the angular size of a star had ever been measured. In the next year, Michelson and Pease measured the diameters of six more red giants before reaching the resolution limit of the 20-foot beam interferometer.<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> <div class="mw-heading mw-heading3"><h3 id="50-foot_Stellar_Interferometer">50-foot Stellar Interferometer</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=10" title="Edit section: 50-foot Stellar Interferometer"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>To expand on the work of the 20-foot interferometer, Pease, Michelson and George E. Hale designed a 50-foot interferometer which was installed at Mount Wilson Observatory in 1929. It successfully measured the diameter of Betelgeuse, but, other than beta Andromedae, could not measure any stars not already measured by the 20-foot interferometer.<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> </p><p>Optical interferometry reached the limit of the available technology and it took about thirty years for faster computing, electronic detectors and lasers to make larger interferometers possible again. </p> <div class="mw-heading mw-heading3"><h3 id="Infrared_Spatial_Interferometer">Infrared Spatial Interferometer</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=11" title="Edit section: Infrared Spatial Interferometer"><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/Infrared_Spatial_Interferometer" title="Infrared Spatial Interferometer">Infrared Spatial Interferometer</a></div> <p>The <a href="/wiki/Infrared_Spatial_Interferometer" title="Infrared Spatial Interferometer">Infrared Spatial Interferometer</a> (ISI), run by an arm of the <a href="/wiki/University_of_California,_Berkeley" title="University of California, Berkeley">University of California, Berkeley</a>, is an array of three 1.65 meter telescopes operating in the mid-infrared. The telescopes are fully mobile and their current site on Mount Wilson allows for placements as far as 70 meters apart, giving the resolution of a telescope of that diameter. The signals are converted to radio frequencies through <a href="/wiki/Heterodyne" title="Heterodyne">heterodyne</a> circuits and then combined electronically using techniques copied from <a href="/wiki/Radio_astronomy" title="Radio astronomy">radio astronomy</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> The longest, 70-meter baseline provides a resolution of 0.003 arcsec at a wavelength of 11 micrometers. On July 9, 2003, ISI recorded the first <a href="/wiki/Closure_phase" title="Closure phase">closure phase</a> <a href="/wiki/Aperture_synthesis" title="Aperture synthesis">aperture synthesis</a> measurements in the mid infrared.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:CHARA_1497.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5c/CHARA_1497.jpg/170px-CHARA_1497.jpg" decoding="async" width="170" height="211" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5c/CHARA_1497.jpg/255px-CHARA_1497.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5c/CHARA_1497.jpg/340px-CHARA_1497.jpg 2x" data-file-width="2090" data-file-height="2590" /></a><figcaption>One of six telescopes of the <a href="/wiki/CHARA_array" title="CHARA array">CHARA array</a></figcaption></figure> <div class="mw-heading mw-heading3"><h3 id="CHARA_array">CHARA array</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=12" title="Edit section: CHARA array"><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/CHARA_array" title="CHARA array">CHARA array</a></div> <p>The <a href="/wiki/CHARA_array" title="CHARA array">Center for High Angular Resolution Astronomy</a> (CHARA), built and operated by <a href="/wiki/Georgia_State_University" title="Georgia State University">Georgia State University</a>, is an interferometer formed from six 1 meter telescopes arranged along three axes with a maximum separation of 330 m. The light beams travel through vacuum pipes and are delayed and combined optically, requiring a building 100 meters long with movable mirrors on carts to keep the light in phase as the Earth rotates. CHARA began scientific use in 2002 and "routine operations" in early 2004. In the infrared, the integrated image can resolve down to 0.0005 arcseconds. Six telescopes are in regular use for scientific observations and as of late 2005 imaging results are routinely acquired. The array captured the first image of the surface of a <a href="/wiki/Main_sequence_star" class="mw-redirect" title="Main sequence star">main sequence star</a> other than the Sun published in early 2007.<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> </p> <div class="mw-heading mw-heading2"><h2 id="Other_telescopes">Other telescopes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=13" title="Edit section: Other telescopes"><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:20180328_Caltech_IR_telescope_Udvar-Hazy.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4d/20180328_Caltech_IR_telescope_Udvar-Hazy.jpg/220px-20180328_Caltech_IR_telescope_Udvar-Hazy.jpg" decoding="async" width="220" height="330" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4d/20180328_Caltech_IR_telescope_Udvar-Hazy.jpg/330px-20180328_Caltech_IR_telescope_Udvar-Hazy.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4d/20180328_Caltech_IR_telescope_Udvar-Hazy.jpg/440px-20180328_Caltech_IR_telescope_Udvar-Hazy.jpg 2x" data-file-width="3840" data-file-height="5760" /></a><figcaption>Caltech Infrared Telescope in the museum</figcaption></figure> <p>A 61 cm telescope fitted with an infrared detector purchased from a military contractor was used by <a href="/wiki/Eric_Becklin" title="Eric Becklin">Eric Becklin</a> in 1966 to determine the center of the <a href="/wiki/Milky_Way" title="Milky Way">Milky Way</a> for the first time.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> </p><p>In 1968, the first large-area near-IR (2.2 μm) survey of the sky was conducted by <a href="/wiki/Gerry_Neugebauer" title="Gerry Neugebauer">Gerry Neugebauer</a> and <a href="/wiki/Robert_B._Leighton" title="Robert B. Leighton">Robert B. Leighton</a> using a 157 cm reflecting dish they had built in the early 1960s.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> Known as the <b>Caltech Infrared Telescope</b>, it operated in an unguided <a href="/wiki/Drift_scan" class="mw-redirect" title="Drift scan">drift scanning</a> mode using a <a href="/wiki/Lead(II)_sulfide" title="Lead(II) sulfide">lead(II) sulfide</a> (PbS) <a href="/wiki/Photomultiplier" title="Photomultiplier">photomultiplier</a> read out on paper charts.<sup id="cite_ref-caltech_infrared_telescope_26-0" class="reference"><a href="#cite_note-caltech_infrared_telescope-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> The telescope is now on display at the <a href="/wiki/Udvar-Hazy_Center" class="mw-redirect" title="Udvar-Hazy Center">Udvar-Hazy Center</a>, part of the <a href="/wiki/Smithsonian_Air_and_Space_Museum" class="mw-redirect" title="Smithsonian Air and Space Museum">Smithsonian Air and Space Museum</a>.<sup id="cite_ref-caltech_infrared_telescope_26-1" class="reference"><a href="#cite_note-caltech_infrared_telescope-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Events">Events</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=14" title="Edit section: Events"><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:PSM_V68_D288_Snow_telescope_house_solar_observatory_on_mount_wilson.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5e/PSM_V68_D288_Snow_telescope_house_solar_observatory_on_mount_wilson.png/220px-PSM_V68_D288_Snow_telescope_house_solar_observatory_on_mount_wilson.png" decoding="async" width="220" height="162" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5e/PSM_V68_D288_Snow_telescope_house_solar_observatory_on_mount_wilson.png/330px-PSM_V68_D288_Snow_telescope_house_solar_observatory_on_mount_wilson.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5e/PSM_V68_D288_Snow_telescope_house_solar_observatory_on_mount_wilson.png/440px-PSM_V68_D288_Snow_telescope_house_solar_observatory_on_mount_wilson.png 2x" data-file-width="1576" data-file-height="1163" /></a><figcaption>The Snow solar telescope (1906)</figcaption></figure> <ul><li>Letters to the Mount Wilson Observatory are the subject of a permanent exhibition at the <a href="/wiki/Museum_of_Jurassic_Technology" title="Museum of Jurassic Technology">Museum of Jurassic Technology</a> in <a href="/wiki/Los_Angeles,_California" class="mw-redirect" title="Los Angeles, California">Los Angeles, California</a>. A small room is dedicated to a collection of unusual letters and theories received by the observatory circa 1915–1935. These letters were also collected in the book <i>No One May Ever Have the Same Knowledge Again: Letters to Mt. Wilson Observatory 1915–1935</i> (<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><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-9647215-0-3" title="Special:BookSources/0-9647215-0-3">0-9647215-0-3</a>).</li> <li>The historic monument came under threat during the <a href="/wiki/August_2009_California_wildfires" class="mw-redirect" title="August 2009 California wildfires">August 2009 California wildfires</a>.<sup id="cite_ref-Mozingo2009_27-0" class="reference"><a href="#cite_note-Mozingo2009-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup></li> <li>The English poet <a href="/wiki/Alfred_Noyes" title="Alfred Noyes">Alfred Noyes</a> was present for the "first light" of the Hooker telescope on November 2, 1917. Noyes used this night as the setting in the opening of <i>Watchers of the Sky,</i> the first volume in his trilogy <i>The Torchbearers</i>, an epic poem about the history of science. According to his account of the night, the first object viewed in the telescope was Jupiter, and Noyes himself was the first to see one of the planet's moons through the telescope.<sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup></li> <li>In September 2020, the observatory was evacuated due to the <a href="/wiki/Bobcat_Fire" title="Bobcat Fire">Bobcat Fire</a>.<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> Flames approached within 500 feet (150 m) of the observatory on September 15,<sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-la_32-0" class="reference"><a href="#cite_note-la-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> but the observatory was declared safe on September 19.<sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup></li> <li>In January 2025, the observatory was evacuated due to the <a href="/wiki/Eaton_Fire" title="Eaton Fire">Eaton Fire</a>, which approached Mount Wilson on January 9.<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Sunday_Afternoon_Concerts_in_the_Dome">Sunday Afternoon Concerts in the Dome</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=15" title="Edit section: Sunday Afternoon Concerts in the Dome"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>On one Sunday each month during the warmer months of the year, Mt. Wilson Observatory hosts a chamber music or jazz concert in the dome.<sup id="cite_ref-Braz_2023_35-0" class="reference"><a href="#cite_note-Braz_2023-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> The idea to use the dome as a venue for live music originated in 2017 from a conversation between Dan Kohne, a board member of the Mt. Wilson Institute, and Cécilia Tsan, an internationally recognized cellist.<sup id="cite_ref-Adamek_2021_36-0" class="reference"><a href="#cite_note-Adamek_2021-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> Tsan agreed that the acoustics in the dome were "extraordinary", comparable to such world-renowned venues as the <a href="/wiki/Palais_Garnier" title="Palais Garnier">Palais Garnier</a> (Opéra de Paris) and the <a href="/wiki/Thomas_Jefferson_Building#Coolidge_Auditorium" title="Thomas Jefferson Building">Coolidge Auditorium</a> at the Library of Congress.<sup id="cite_ref-Kaan_2021_37-0" class="reference"><a href="#cite_note-Kaan_2021-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> Kohne and Tsan worked together to create the series, which has run every concert season except for a break during the <a href="/wiki/Covid-19_pandemic" class="mw-redirect" title="Covid-19 pandemic">Covid-19 pandemic</a>. Given that the observatory is no longer able to do significant research due to light pollution, it receives no scientific funding; the concerts therefore provide a significant portion of the budget needed to maintain the observatory as an historic landmark, along with ticketed events such as public viewing nights.<sup id="cite_ref-Purtill_2023_38-0" class="reference"><a href="#cite_note-Purtill_2023-38"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="In_popular_culture">In popular culture</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Mount_Wilson_Observatory&action=edit&section=16" title="Edit section: In popular culture"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The observatory was the primary setting of "Nothing Behind the Door," the first episode of the radio series <a href="/wiki/Quiet,_Please" title="Quiet, Please">Quiet, Please</a> which originally aired June 8, 1947. </p><p>The observatory was a filming location in a space-themed episode of <i><a href="/wiki/Check_It_Out!_with_Dr._Steve_Brule" title="Check It Out! with Dr. Steve Brule">Check It Out! with Dr. Steve Brule</a></i>. </p> <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=Mount_Wilson_Observatory&action=edit&section=17" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/List_of_largest_optical_reflecting_telescopes" title="List of largest optical reflecting telescopes">List of largest optical reflecting telescopes</a></li> <li><a href="/wiki/List_of_largest_optical_telescopes_historically" title="List of largest optical telescopes historically">List of largest optical telescopes historically</a></li> <li><a href="/wiki/List_of_largest_optical_telescopes_in_the_20th_century" title="List of largest optical telescopes in the 20th century">List of largest optical telescopes in the 20th century</a></li> <li><a href="/wiki/List_of_observatories" class="mw-redirect" title="List of observatories">List of observatories</a></li> <li><a href="/wiki/Mount_Wilson_Toll_Road" title="Mount Wilson Toll Road">Mount Wilson Toll Road</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=Mount_Wilson_Observatory&action=edit&section=18" 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-lat-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-lat_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-lat_1-1"><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="CITEREFHansen2008" class="citation news cs1">Hansen, Wendy (July 6, 2008). <a rel="nofollow" class="external text" href="http://www.latimes.com/news/local/la-me-then6-2008jul06,0,6407442.story">"Mount Wilson Observatory an astronomical gem"</a>. <i><a href="/wiki/Los_Angeles_Times" title="Los Angeles Times">Los Angeles Times</a></i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Los+Angeles+Times&rft.atitle=Mount+Wilson+Observatory+an+astronomical+gem&rft.date=2008-07-06&rft.aulast=Hansen&rft.aufirst=Wendy&rft_id=http%3A%2F%2Fwww.latimes.com%2Fnews%2Flocal%2Fla-me-then6-2008jul06%2C0%2C6407442.story&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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">Harris Newmark, <i>Sixty Years in Southern California</i> (1916).</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"><a rel="nofollow" class="external text" href="http://www.sgvtribune.com/search/ci_6674075?IADID=Search-www.sgvtribune.com-www.sgvtribune.com">Window to other worlds - SGVTribune.com</a></span> </li> <li id="cite_note-mtwilson.edu-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-mtwilson.edu_4-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-mtwilson.edu_4-1"><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 class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20150712005138/http://www.mtwilson.edu/Simmons2.html">"Mount Wilson Observatory"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.mtwilson.edu/Simmons2.html">the original</a> on July 12, 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">August 11,</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mount+Wilson+Observatory&rft_id=http%3A%2F%2Fwww.mtwilson.edu%2FSimmons2.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></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"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFTurner" class="citation web cs1">Turner, Paula C. <a rel="nofollow" class="external text" href="http://physics.kenyon.edu/people/turner/cureaweb/turner_aas07poster.pdf">"The CUREA Program at Mount Wilson"</a> <span class="cs1-format">(PDF)</span>. <a href="/wiki/Kenyon_College" title="Kenyon College">Kenyon College</a><span class="reference-accessdate">. Retrieved <span class="nowrap">September 21,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+CUREA+Program+at+Mount+Wilson&rft.pub=Kenyon+College&rft.aulast=Turner&rft.aufirst=Paula+C.&rft_id=http%3A%2F%2Fphysics.kenyon.edu%2Fpeople%2Fturner%2Fcureaweb%2Fturner_aas07poster.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></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="CITEREFPinkertonChen" class="citation web cs1">Pinkerton, Stephen; Chen, Casey. <a rel="nofollow" class="external text" href="http://physics1.usc.edu/solar/history.html">"History of the 60 Foot Solar Tower"</a>. <a href="/wiki/University_of_Southern_California" title="University of Southern California">University of Southern California</a><span class="reference-accessdate">. Retrieved <span class="nowrap">September 21,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=History+of+the+60+Foot+Solar+Tower&rft.pub=University+of+Southern+California&rft.aulast=Pinkerton&rft.aufirst=Stephen&rft.au=Chen%2C+Casey&rft_id=http%3A%2F%2Fphysics1.usc.edu%2Fsolar%2Fhistory.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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="CITEREFGilman2003" class="citation web cs1">Gilman, Pam (2003). <a rel="nofollow" class="external text" href="http://obs.astro.ucla.edu/150_hist.html">"The 150-Foot Solar Tower: History"</a>. <a href="/wiki/University_of_California,_Los_Angeles" title="University of California, Los Angeles">University of California, Los Angeles</a><span class="reference-accessdate">. Retrieved <span class="nowrap">September 21,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+150-Foot+Solar+Tower%3A+History&rft.pub=University+of+California%2C+Los+Angeles&rft.date=2003&rft.aulast=Gilman&rft.aufirst=Pam&rft_id=http%3A%2F%2Fobs.astro.ucla.edu%2F150_hist.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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://web.archive.org/web/20150905105144/http://www.mtwilson.edu/Simmons3.html">"Mount Wilson Observatory"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.mtwilson.edu/Simmons3.html">the original</a> on September 5, 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">August 11,</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mount+Wilson+Observatory&rft_id=http%3A%2F%2Fwww.mtwilson.edu%2FSimmons3.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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 class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20131228071438/http://www.mtwilson.edu/60-inch/60inVisitorPackage.pdf">"Astronomical Observing through the Mount Wilson 60-inch Telescope"</a> <span class="cs1-format">(PDF)</span>. Archived from <a rel="nofollow" class="external text" href="http://www.mtwilson.edu/60-inch/60inVisitorPackage.pdf">the original</a> <span class="cs1-format">(PDF)</span> on December 28, 2013.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Astronomical+Observing+through+the+Mount+Wilson+60-inch+Telescope&rft_id=http%3A%2F%2Fwww.mtwilson.edu%2F60-inch%2F60inVisitorPackage.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPurtill2023" class="citation news cs1">Purtill, Corinne (October 3, 2023). <a rel="nofollow" class="external text" href="https://www.latimes.com/science/story/2023-10-03/saving-mt-wilson-observatory-battle-maintain-spot-found-universe">"The battle to save Mt. Wilson Observatory, where we found our place in the universe"</a>. <i>Los Angeles Times</i><span class="reference-accessdate">. Retrieved <span class="nowrap">October 3,</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Los+Angeles+Times&rft.atitle=The+battle+to+save+Mt.+Wilson+Observatory%2C+where+we+found+our+place+in+the+universe&rft.date=2023-10-03&rft.aulast=Purtill&rft.aufirst=Corinne&rft_id=https%3A%2F%2Fwww.latimes.com%2Fscience%2Fstory%2F2023-10-03%2Fsaving-mt-wilson-observatory-battle-maintain-spot-found-universe&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://archives.chicagotribune.com/1938/08/30/page/1/article/4-more-testify-to-seeing-hines-with-racketeer">Chicago Tribune archives</a>- Retrieved 2017-05-16</span> </li> <li id="cite_note-NYT-1907-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-NYT-1907_12-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFServiss,_Garrett_P.1907" class="citation cs2">Serviss, Garrett P. (January 27, 1907), <a rel="nofollow" class="external text" href="https://timesmachine.nytimes.com/timesmachine/1907/01/27/106737435.pdf">"The Greatest Telescope in the World; Monster Instrument Ordered by Carnegie Institution Will Far Exceed in Power All Other Watchers of the Skies"</a> <span class="cs1-format">(PDF)</span>, <i>New York Times</i></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=New+York+Times&rft.atitle=The+Greatest+Telescope+in+the+World%3B+Monster+Instrument+Ordered+by+Carnegie+Institution+Will+Far+Exceed+in+Power+All+Other+Watchers+of+the+Skies&rft.date=1907-01-27&rft.au=Serviss%2C+Garrett+P.&rft_id=https%3A%2F%2Ftimesmachine.nytimes.com%2Ftimesmachine%2F1907%2F01%2F27%2F106737435.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.mtwilson.edu/index.html">History of Mount Wilson Observatory - Building the 2.5 meter Telescope</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20150905060014/http://www.mtwilson.edu/index.html">Archived</a> 2015-09-05 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a>. Article written by Mike Simmons in 1984 for the <i>Mount Wilson Observatory Association</i> (MWOA).</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="CITEREFBonnier_Corporation1935" class="citation magazine cs1">Bonnier Corporation (July 1935). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=ySUDAAAAMBAJ&pg=PA17">"Aluminum-Coated Mirrors Boost Power of Giant Telescope"</a>. <i>Popular Science</i>. Bonnier Corporation. p. 17.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Popular+Science&rft.atitle=Aluminum-Coated+Mirrors+Boost+Power+of+Giant+Telescope&rft.pages=17&rft.date=1935-07&rft.au=Bonnier+Corporation&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DySUDAAAAMBAJ%26pg%3DPA17&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</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="http://calteches.library.caltech.edu/997/1/Telescope.pdf">"Engineering and Science monthly May 1949"</a> <span class="cs1-format">(PDF)</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Engineering+and+Science+monthly+May+1949&rft_id=http%3A%2F%2Fcalteches.library.caltech.edu%2F997%2F1%2FTelescope.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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 web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20150529195621/http://www.mtwilson.edu/cent.html">"Mount Wilson Observatory"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.mtwilson.edu/cent.html">the original</a> on May 29, 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">August 11,</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mount+Wilson+Observatory&rft_id=http%3A%2F%2Fwww.mtwilson.edu%2Fcent.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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="CITEREFThompson2013" class="citation web cs1"><a href="/wiki/Laird_A._Thompson" title="Laird A. Thompson">Thompson, Laird A.</a> (September 2, 2013). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20150905090019/http://www.lairdthompson.net/">"Laird A. Thompson: Professor of Astronomy"</a>. <i>jc-t.com</i>. Archived from <a rel="nofollow" class="external text" href="http://www.lairdthompson.net/">the original</a> on September 5, 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">September 21,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=jc-t.com&rft.atitle=Laird+A.+Thompson%3A+Professor+of+Astronomy&rft.date=2013-09-02&rft.aulast=Thompson&rft.aufirst=Laird+A.&rft_id=http%3A%2F%2Fwww.lairdthompson.net%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</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/20150905060025/http://www.mtwilson.edu/100in.html">"Mount Wilson Observatory"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.mtwilson.edu/100in.html">the original</a> on September 5, 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">August 11,</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mount+Wilson+Observatory&rft_id=http%3A%2F%2Fwww.mtwilson.edu%2F100in.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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 class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20150712085353/http://www.mtwilson.edu/vir/100/20fti/">"Mount Wilson Observatory"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.mtwilson.edu/vir/100/20fti/">the original</a> on July 12, 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">August 20,</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mount+Wilson+Observatory&rft_id=http%3A%2F%2Fwww.mtwilson.edu%2Fvir%2F100%2F20fti%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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="CITEREFVaughan1967" class="citation journal cs1">Vaughan, Arthur H. Jr. (August 1967). <a rel="nofollow" class="external text" href="http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1967ASPL...10...57V&db_key=AST&page_ind=0&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES">"Interferometer Measurement of Star Diameters"</a>. <i><a href="/wiki/Astronomical_Society_of_the_Pacific" title="Astronomical Society of the Pacific">Astronomical Society of the Pacific</a></i>. <b>10</b> (458): 57. <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/1967ASPL...10...57V">1967ASPL...10...57V</a><span class="reference-accessdate">. Retrieved <span class="nowrap">September 21,</span> 2020</span>.</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&rft.atitle=Interferometer+Measurement+of+Star+Diameters&rft.volume=10&rft.issue=458&rft.pages=57&rft.date=1967-08&rft_id=info%3Abibcode%2F1967ASPL...10...57V&rft.aulast=Vaughan&rft.aufirst=Arthur+H.+Jr.&rft_id=http%3A%2F%2Farticles.adsabs.harvard.edu%2Fcgi-bin%2Fnph-iarticle_query%3Fbibcode%3D1967ASPL...10...57V%26db_key%3DAST%26page_ind%3D0%26plate_select%3DNO%26data_type%3DGIF%26type%3DSCREEN_GIF%26classic%3DYES&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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 web cs1"><a rel="nofollow" class="external text" href="http://isi.ssl.berkeley.edu/system_overview.htm">"Infrared Spatial Interferometer Array – System Overview"</a>. <i>University of California at Berkeley</i><span class="reference-accessdate">. Retrieved <span class="nowrap">August 31,</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=University+of+California+at+Berkeley&rft.atitle=Infrared+Spatial+Interferometer+Array+%E2%80%93+System+Overview&rft_id=http%3A%2F%2Fisi.ssl.berkeley.edu%2Fsystem_overview.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFA._A._ChandlerK._TatebeD._D._S._HaleC._H._Townes2007" class="citation web cs1">A. A. Chandler; K. Tatebe; D. D. S. Hale; C. H. Townes (March 10, 2007). <a rel="nofollow" class="external text" href="http://isi.ssl.berkeley.edu/papers/Chandler2007ApJ657.pdf">"The Radiative Pattern and Asymmetry of IRC +10216 at 11 μm Measured with Interferometry and Closure Phase"</a> <span class="cs1-format">(PDF)</span>. <i>Space Sciences Laboratory and Department of Physics, University of California, Berkeley, CA</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Space+Sciences+Laboratory+and+Department+of+Physics%2C+University+of+California%2C+Berkeley%2C+CA&rft.atitle=The+Radiative+Pattern+and+Asymmetry+of+IRC+%2B10216+at+11+%CE%BCm+Measured+with+Interferometry+and+Closure+Phase&rft.date=2007-03-10&rft.au=A.+A.+Chandler&rft.au=K.+Tatebe&rft.au=D.+D.+S.+Hale&rft.au=C.+H.+Townes&rft_id=http%3A%2F%2Fisi.ssl.berkeley.edu%2Fpapers%2FChandler2007ApJ657.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></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"><a rel="nofollow" class="external text" href="http://www.ns.umich.edu/htdocs/releases/story.php?id=5877">U-M astronomers capture the first image of surface features on a sun-like star</a>, <a href="/wiki/University_of_Michigan" title="University of Michigan">University of Michigan</a>, 2007-05-31</span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</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://www.pbs.org/wgbh/nova/transcripts/3314_blackhol.html">"Monster of the Milky Way"</a>. <i><a href="/wiki/Nova_(American_TV_series)" class="mw-redirect" title="Nova (American TV series)">NOVA</a></i>. <a href="/wiki/PBS" title="PBS">PBS</a>. October 31, 2006<span class="reference-accessdate">. Retrieved <span class="nowrap">September 21,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=NOVA&rft.atitle=Monster+of+the+Milky+Way&rft.date=2006-10-31&rft_id=https%3A%2F%2Fwww.pbs.org%2Fwgbh%2Fnova%2Ftranscripts%2F3314_blackhol.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</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/20080528035728/http://www.astro.psu.edu/users/kluhman/a597/Lec3.pdf">"1968: Two Micron Sky Survey"</a> <span class="cs1-format">(PDF)</span>. Archived from <a rel="nofollow" class="external text" href="http://www.astro.psu.edu/users/kluhman/a597/Lec3.pdf">the original</a> <span class="cs1-format">(PDF)</span> on May 28, 2008<span class="reference-accessdate">. Retrieved <span class="nowrap">September 21,</span> 2020</span> – via <a href="/wiki/Pennsylvania_State_University" title="Pennsylvania State University">Pennsylvania State University</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=1968%3A+Two+Micron+Sky+Survey&rft_id=http%3A%2F%2Fwww.astro.psu.edu%2Fusers%2Fkluhman%2Fa597%2FLec3.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-caltech_infrared_telescope-26"><span class="mw-cite-backlink">^ <a href="#cite_ref-caltech_infrared_telescope_26-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-caltech_infrared_telescope_26-1"><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 class="citation web cs1"><a rel="nofollow" class="external text" href="https://airandspace.si.edu/collection-objects/reflecting-telescope-infrared-caltech">"Reflecting Telescope, Infrared, Caltech"</a>. <i>National Air and Space Museum</i>. March 20, 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">March 19,</span> 2018</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=National+Air+and+Space+Museum&rft.atitle=Reflecting+Telescope%2C+Infrared%2C+Caltech&rft.date=2016-03-20&rft_id=https%3A%2F%2Fairandspace.si.edu%2Fcollection-objects%2Freflecting-telescope-infrared-caltech&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-Mozingo2009-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-Mozingo2009_27-0">^</a></b></span> <span class="reference-text">Mozingo, Joe (August 30, 2009). <a rel="nofollow" class="external text" href="http://latimesblogs.latimes.com/lanow/2009/08/station-fire-approaching-historic-mt-wilson-observatory-fire-officials-say.html">Station fire likely to hit historic Mt. Wilson observatory, fire officials say.</a> <i><a href="/wiki/Los_Angeles_Times" title="Los Angeles Times">Los Angeles Times</a></i></span> </li> <li id="cite_note-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-28">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFNoyes1922" class="citation book cs1"><a href="/wiki/Alfred_Noyes" title="Alfred Noyes">Noyes, Alfred</a> (1922). <a rel="nofollow" class="external text" href="https://archive.org/details/watcherssky00noyegoog"><i>Watchers of the Sky</i></a>. New York, Frederick A. Stokes.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Watchers+of+the+Sky&rft.pub=New+York%2C+Frederick+A.+Stokes&rft.date=1922&rft.aulast=Noyes&rft.aufirst=Alfred&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fwatcherssky00noyegoog&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-29">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFStaff" class="citation news cs1">Staff, -LAist. <a rel="nofollow" class="external text" href="https://laist.com/latest/post/20200914/bobcat-fire-day9">"Bobcat Fire: Blaze Grows To Over 38K Acres; Serious Threat To Mt. Wilson"</a>. <i>LAist</i><span class="reference-accessdate">. Retrieved <span class="nowrap">September 15,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=LAist&rft.atitle=Bobcat+Fire%3A+Blaze+Grows+To+Over+38K+Acres%3B+Serious+Threat+To+Mt.+Wilson&rft.aulast=Staff&rft.aufirst=-LAist&rft_id=https%3A%2F%2Flaist.com%2Flatest%2Fpost%2F20200914%2Fbobcat-fire-day9&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-30"><span class="mw-cite-backlink"><b><a href="#cite_ref-30">^</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="https://ktla.com/news/local-news/bobcat-fire-grows-to-more-than-36000-acres-officials-plan-virtual-meeting-with-public-monday-evening/">"Bobcat Fire grows to nearly 38,300 acres, jumping contingency line; Sierra Madre residents urged to prepare to flee"</a>. <i>KTLA</i>. September 14, 2020<span class="reference-accessdate">. Retrieved <span class="nowrap">September 15,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=KTLA&rft.atitle=Bobcat+Fire+grows+to+nearly+38%2C300+acres%2C+jumping+contingency+line%3B+Sierra+Madre+residents+urged+to+prepare+to+flee&rft.date=2020-09-14&rft_id=https%3A%2F%2Fktla.com%2Fnews%2Flocal-news%2Fbobcat-fire-grows-to-more-than-36000-acres-officials-plan-virtual-meeting-with-public-monday-evening%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-31">^</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="https://www.latimes.com/california/story/2020-09-16/new-evacuations-as-bobcat-fire-jumps-north-firefighters-battle-at-mt-wilson">"Bobcat fire threatens multiple fronts, from Mt. Wilson to foothill neighborhoods"</a>. <i>Los Angeles Times</i>. September 16, 2020<span class="reference-accessdate">. Retrieved <span class="nowrap">September 18,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Los+Angeles+Times&rft.atitle=Bobcat+fire+threatens+multiple+fronts%2C+from+Mt.+Wilson+to+foothill+neighborhoods&rft.date=2020-09-16&rft_id=https%3A%2F%2Fwww.latimes.com%2Fcalifornia%2Fstory%2F2020-09-16%2Fnew-evacuations-as-bobcat-fire-jumps-north-firefighters-battle-at-mt-wilson&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-la-32"><span class="mw-cite-backlink"><b><a href="#cite_ref-la_32-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSmith2020" class="citation news cs1">Smith, Hayley (September 17, 2020). <a rel="nofollow" class="external text" href="https://www.latimes.com/california/story/2020-09-17/evacuation-warnings-for-antelope-valley-as-bobcat-fire-expands">"Evacuations ordered in parts of Antelope Valley as Bobcat fire moves within 1 mile of Juniper Hills"</a>. <i>Los Angeles Times</i><span class="reference-accessdate">. Retrieved <span class="nowrap">September 18,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Los+Angeles+Times&rft.atitle=Evacuations+ordered+in+parts+of+Antelope+Valley+as+Bobcat+fire+moves+within+1+mile+of+Juniper+Hills&rft.date=2020-09-17&rft.aulast=Smith&rft.aufirst=Hayley&rft_id=https%3A%2F%2Fwww.latimes.com%2Fcalifornia%2Fstory%2F2020-09-17%2Fevacuation-warnings-for-antelope-valley-as-bobcat-fire-expands&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-33"><span class="mw-cite-backlink"><b><a href="#cite_ref-33">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFOverbye2020" class="citation news cs1">Overbye, Dennis (September 19, 2020). <a rel="nofollow" class="external text" href="https://www.nytimes.com/2020/09/19/science/wilson-observatory-bobcat-wildfires.html">"Mount Wilson Observatory Survives a Trial by Fire"</a>. <i>The New York Times</i><span class="reference-accessdate">. Retrieved <span class="nowrap">September 20,</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=Mount+Wilson+Observatory+Survives+a+Trial+by+Fire&rft.date=2020-09-19&rft.aulast=Overbye&rft.aufirst=Dennis&rft_id=https%3A%2F%2Fwww.nytimes.com%2F2020%2F09%2F19%2Fscience%2Fwilson-observatory-bobcat-wildfires.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-34"><span class="mw-cite-backlink"><b><a href="#cite_ref-34">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLloyd_•_•2025" class="citation web cs1">Lloyd • •, Jonathan (January 9, 2025). <a rel="nofollow" class="external text" href="https://www.nbclosangeles.com/news/california-wildfires/eaton-fire-mount-wilson/3599568/">"Eaton Fire flares up near summit of Mount Wilson"</a>. <i>NBC Los Angeles</i><span class="reference-accessdate">. Retrieved <span class="nowrap">January 9,</span> 2025</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=NBC+Los+Angeles&rft.atitle=Eaton+Fire+flares+up+near+summit+of+Mount+Wilson&rft.date=2025-01-09&rft.aulast=Lloyd+%E2%80%A2+%E2%80%A2&rft.aufirst=Jonathan&rft_id=https%3A%2F%2Fwww.nbclosangeles.com%2Fnews%2Fcalifornia-wildfires%2Featon-fire-mount-wilson%2F3599568%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-Braz_2023-35"><span class="mw-cite-backlink"><b><a href="#cite_ref-Braz_2023_35-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBraz2023" class="citation news cs1">Braz, Anna (August 21, 2023). <a rel="nofollow" class="external text" href="https://www.latimes.com/travel/story/2023-08-21/mount-wilson-observatory-dome-music-concert">"One of the most magnificent concert venues in L.A. is the dome of this 100-inch telescope"</a>. Los Angeles Times. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240302111528/https://www.latimes.com/travel/story/2023-08-21/mount-wilson-observatory-dome-music-concert">Archived</a> from the original on March 2, 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">June 15,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=One+of+the+most+magnificent+concert+venues+in+L.A.+is+the+dome+of+this+100-inch+telescope&rft.date=2023-08-21&rft.aulast=Braz&rft.aufirst=Anna&rft_id=https%3A%2F%2Fwww.latimes.com%2Ftravel%2Fstory%2F2023-08-21%2Fmount-wilson-observatory-dome-music-concert&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-Adamek_2021-36"><span class="mw-cite-backlink"><b><a href="#cite_ref-Adamek_2021_36-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAdamek2021" class="citation news cs1">Adamek, Pauline (August 2021). <a rel="nofollow" class="external text" href="https://www.artsbeatla.com/2021/08/jazz-concert-in-the-dome/">"Jazz Concerts in the Dome, Mt. Wilson Observatory"</a>. ArtsBeatLA.com. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20231203042658/https://www.artsbeatla.com/2021/08/jazz-concert-in-the-dome/">Archived</a> from the original on December 3, 2023<span class="reference-accessdate">. Retrieved <span class="nowrap">June 15,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Jazz+Concerts+in+the+Dome%2C+Mt.+Wilson+Observatory&rft.date=2021-08&rft.aulast=Adamek&rft.aufirst=Pauline&rft_id=https%3A%2F%2Fwww.artsbeatla.com%2F2021%2F08%2Fjazz-concert-in-the-dome%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-Kaan_2021-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-Kaan_2021_37-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKaan2021" class="citation news cs1">Kaan, Gil (July 21, 2021). <a rel="nofollow" class="external text" href="https://www.broadwayworld.com/los-angeles/article/BWW-Interview-Cellist-Ccilia-Tsan-On-Combining-Her-Musical-Artistry-With-CONCERTS-Programming-20210721">"Interview: Cellist Cécilia Tsan On Combining Her Musical Artistry With CONCERTS Programming"</a>. BroadwayWorld.com. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20210727054528/https://www.broadwayworld.com/los-angeles/article/BWW-Interview-Cellist-Ccilia-Tsan-On-Combining-Her-Musical-Artistry-With-CONCERTS-Programming-20210721">Archived</a> from the original on July 27, 2021<span class="reference-accessdate">. Retrieved <span class="nowrap">June 15,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Interview%3A+Cellist+C%C3%A9cilia+Tsan+On+Combining+Her+Musical+Artistry+With+CONCERTS+Programming&rft.date=2021-07-21&rft.aulast=Kaan&rft.aufirst=Gil&rft_id=https%3A%2F%2Fwww.broadwayworld.com%2Flos-angeles%2Farticle%2FBWW-Interview-Cellist-Ccilia-Tsan-On-Combining-Her-Musical-Artistry-With-CONCERTS-Programming-20210721&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></span> </li> <li id="cite_note-Purtill_2023-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-Purtill_2023_38-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPurtill2023" class="citation news cs1">Purtill, Corinne (October 3, 2023). <a rel="nofollow" class="external text" href="https://www.yahoo.com/news/saving-mt-wilson-observatory-inside-100012619.html">"Saving Mt. Wilson Observatory: Inside the long battle to maintain the spot where we found our place in the universe"</a>. Los Angeles Times. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20240615101220/https://www.yahoo.com/news/saving-mt-wilson-observatory-inside-100012619.html">Archived</a> from the original on June 15, 2024<span class="reference-accessdate">. Retrieved <span class="nowrap">June 15,</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Saving+Mt.+Wilson+Observatory%3A+Inside+the+long+battle+to+maintain+the+spot+where+we+found+our+place+in+the+universe&rft.date=2023-10-03&rft.aulast=Purtill&rft.aufirst=Corinne&rft_id=https%3A%2F%2Fwww.yahoo.com%2Fnews%2Fsaving-mt-wilson-observatory-inside-100012619.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" 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=Mount_Wilson_Observatory&action=edit&section=19" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Commons-logo.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Mount_Wilson_Observatory" class="extiw" title="commons:Category:Mount Wilson Observatory">Mount Wilson Observatory</a></span>.</div></div> </div> <ul><li><span class="official-website"><span class="url"><a rel="nofollow" class="external text" href="https://www.mtwilson.edu">Official website</a></span></span> <span class="mw-valign-text-top" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q466863#P856" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span> <ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20050316191528/http://www.mtwilson.edu/vir/100/">The 100-inch Hooker Telescope</a></li> <li><a rel="nofollow" class="external text" href="http://www.astro.ucla.edu/~obs/towercam.htm">150-Foot Solar Tower Webcam Image</a></li></ul></li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20041204185309/http://www.chara.gsu.edu/CHARA/index.html">CHARA</a></li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20071215183003/http://isi.ssl.berkeley.edu/">The ISI Array</a></li> <li><a rel="nofollow" class="external text" href="http://cleardarksky.com/c/MtWilsonOBCAkey.html?1">Mount Wilson Observatory Clear Sky Clock</a></li> <li><a rel="nofollow" class="external text" href="http://www.mjt.org/exhibits/letters/letters.html">Letters to the MWO, 1915-1935</a></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHearst_Magazines1931" class="citation magazine cs1">Hearst Magazines (January 1931). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=reMDAAAAMBAJ&pg=RA1-PA42">"Telescope's Five Ton Eye Is Restored With Silver"</a>. <i>Popular Mechanics</i>. Hearst Magazines. p. 1.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Popular+Mechanics&rft.atitle=Telescope%27s+Five+Ton+Eye+Is+Restored+With+Silver&rft.pages=1&rft.date=1931-01&rft.au=Hearst+Magazines&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DreMDAAAAMBAJ%26pg%3DRA1-PA42&rfr_id=info%3Asid%2Fen.wikipedia.org%3AMount+Wilson+Observatory" class="Z3988"></span></li> <li><a rel="nofollow" class="external text" href="http://digital2.library.ucla.edu/viewItem.do?ark=21198/zz002cx1q3">Image of the sixty inch telescope at the Mount Wilson Observatory, 1920-1939.</a> <a href="/wiki/Los_Angeles_Times" title="Los Angeles Times">Los Angeles Times</a> Photographic Archive (Collection 1429). UCLA Library Special Collections, <a href="/wiki/Charles_E._Young_Research_Library" title="Charles E. Young Research Library">Charles E. Young Research Library</a>, <a href="/wiki/University_of_California,_Los_Angeles" title="University of California, Los Angeles">University of California, Los Angeles</a>.</li></ul> <style data-mw-deduplicate="TemplateStyles:r1130092004">.mw-parser-output .portal-bar{font-size:88%;font-weight:bold;display:flex;justify-content:center;align-items:baseline}.mw-parser-output .portal-bar-bordered{padding:0 2em;background-color:#fdfdfd;border:1px solid #a2a9b1;clear:both;margin:1em auto 0}.mw-parser-output .portal-bar-related{font-size:100%;justify-content:flex-start}.mw-parser-output .portal-bar-unbordered{padding:0 1.7em;margin-left:0}.mw-parser-output .portal-bar-header{margin:0 1em 0 0.5em;flex:0 0 auto;min-height:24px}.mw-parser-output .portal-bar-content{display:flex;flex-flow:row wrap;flex:0 1 auto;padding:0.15em 0;column-gap:1em;align-items:baseline;margin:0;list-style:none}.mw-parser-output .portal-bar-content-related{margin:0;list-style:none}.mw-parser-output .portal-bar-item{display:inline-block;margin:0.15em 0.2em;min-height:24px;line-height:24px}@media screen and (max-width:768px){.mw-parser-output .portal-bar{font-size:88%;font-weight:bold;display:flex;flex-flow:column wrap;align-items:baseline}.mw-parser-output .portal-bar-header{text-align:center;flex:0;padding-left:0.5em;margin:0 auto}.mw-parser-output .portal-bar-related{font-size:100%;align-items:flex-start}.mw-parser-output .portal-bar-content{display:flex;flex-flow:row wrap;align-items:center;flex:0;column-gap:1em;border-top:1px solid #a2a9b1;margin:0 auto;list-style:none}.mw-parser-output .portal-bar-content-related{border-top:none;margin:0;list-style:none}}.mw-parser-output .navbox+link+.portal-bar,.mw-parser-output .navbox+style+.portal-bar,.mw-parser-output .navbox+link+.portal-bar-bordered,.mw-parser-output .navbox+style+.portal-bar-bordered,.mw-parser-output .sister-bar+link+.portal-bar,.mw-parser-output .sister-bar+style+.portal-bar,.mw-parser-output .portal-bar+.navbox-styles+.navbox,.mw-parser-output .portal-bar+.navbox-styles+.sister-bar{margin-top:-1px}</style><div class="portal-bar noprint metadata noviewer portal-bar-bordered" role="navigation" aria-label="Portals"><span class="portal-bar-header"><a href="/wiki/Wikipedia:Contents/Portals" title="Wikipedia:Contents/Portals">Portals</a>:</span><ul class="portal-bar-content"><li class="portal-bar-item"><span class="nowrap"><span class="mw-image-border" typeof="mw:File"><span><img alt="flag" src="//upload.wikimedia.org/wikipedia/commons/thumb/0/01/Flag_of_California.svg/21px-Flag_of_California.svg.png" decoding="async" width="21" height="14" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/01/Flag_of_California.svg/32px-Flag_of_California.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/01/Flag_of_California.svg/42px-Flag_of_California.svg.png 2x" data-file-width="900" data-file-height="600" /></span></span> </span><a href="/wiki/Portal:California" title="Portal:California">California</a></li><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/19px-Crab_Nebula.jpg" decoding="async" width="19" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/29px-Crab_Nebula.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/00/Crab_Nebula.jpg/38px-Crab_Nebula.jpg 2x" data-file-width="3864" data-file-height="3864" /></span></span> </span><a href="/wiki/Portal:Astronomy" title="Portal:Astronomy">Astronomy</a></li><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><a href="/wiki/File:He1523a.jpg" class="mw-file-description"><img alt="icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5f/He1523a.jpg/16px-He1523a.jpg" decoding="async" width="16" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5f/He1523a.jpg/25px-He1523a.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5f/He1523a.jpg/33px-He1523a.jpg 2x" data-file-width="180" data-file-height="207" /></a></span> </span><a href="/wiki/Portal:Stars" title="Portal:Stars">Stars</a></li><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/RocketSunIcon.svg/19px-RocketSunIcon.svg.png" decoding="async" width="19" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/RocketSunIcon.svg/29px-RocketSunIcon.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d6/RocketSunIcon.svg/38px-RocketSunIcon.svg.png 2x" data-file-width="128" data-file-height="128" /></span></span> </span><a href="/wiki/Portal:Spaceflight" title="Portal:Spaceflight">Spaceflight</a></li><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/21px-Earth-moon.jpg" decoding="async" width="21" height="17" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/32px-Earth-moon.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Earth-moon.jpg/42px-Earth-moon.jpg 2x" data-file-width="3000" data-file-height="2400" /></span></span> </span><a href="/wiki/Portal:Outer_space" title="Portal:Outer space">Outer space</a></li><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/8/83/Solar_system.jpg/15px-Solar_system.jpg" decoding="async" width="15" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/83/Solar_system.jpg/23px-Solar_system.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/83/Solar_system.jpg/30px-Solar_system.jpg 2x" data-file-width="4500" data-file-height="5600" /></span></span> </span><a href="/wiki/Portal:Solar_System" title="Portal:Solar System">Solar System</a></li><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><a href="/wiki/File:Diploma_icon.png" class="mw-file-description"><img alt="icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/7/76/Diploma_icon.png/19px-Diploma_icon.png" decoding="async" width="19" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/76/Diploma_icon.png/29px-Diploma_icon.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/76/Diploma_icon.png/38px-Diploma_icon.png 2x" data-file-width="128" data-file-height="128" /></a></span> </span><a href="/wiki/Portal:Education" class="mw-redirect" title="Portal:Education">Education</a></li><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><a href="/wiki/File:Nuvola_apps_kalzium.svg" class="mw-file-description"><img alt="icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Nuvola_apps_kalzium.svg/19px-Nuvola_apps_kalzium.svg.png" decoding="async" width="19" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Nuvola_apps_kalzium.svg/29px-Nuvola_apps_kalzium.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Nuvola_apps_kalzium.svg/38px-Nuvola_apps_kalzium.svg.png 2x" data-file-width="128" data-file-height="128" /></a></span> </span><a href="/wiki/Portal:Science" title="Portal:Science">Science</a></li></ul></div> <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 li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style><style data-mw-deduplicate="TemplateStyles:r1038841319">.mw-parser-output .tooltip-dotted{border-bottom:1px dotted;cursor:help}</style></div><div role="navigation" class="navbox authority-control" aria-labelledby="Authority_control_databases_frameless&#124;text-top&#124;10px&#124;alt=Edit_this_at_Wikidata&#124;link=https&#58;//www.wikidata.org/wiki/Q466863#identifiers&#124;class=noprint&#124;Edit_this_at_Wikidata1277" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div id="Authority_control_databases_frameless&#124;text-top&#124;10px&#124;alt=Edit_this_at_Wikidata&#124;link=https&#58;//www.wikidata.org/wiki/Q466863#identifiers&#124;class=noprint&#124;Edit_this_at_Wikidata1277" style="font-size:114%;margin:0 4em"><a href="/wiki/Help:Authority_control" title="Help:Authority control">Authority control databases</a> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q466863#identifiers" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">International</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://isni.org/isni/0000000121688877">ISNI</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://viaf.org/viaf/139038373">VIAF</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="http://id.worldcat.org/fast/567378/">FAST</a></span></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">National</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://d-nb.info/gnd/505707-3">Germany</a></span></li><li><span class="uid"><span class="rt-commentedText tooltip tooltip-dotted" title="Mount Wilson Observatory"><a rel="nofollow" class="external text" href="https://id.loc.gov/authorities/n82051171">United States</a></span></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://authority.bibsys.no/authority/rest/authorities/html/5093258">Norway</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://www.nli.org.il/en/authorities/987011289496105171">Israel</a></span></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Artists</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://www.moma.org/artists/64073">Museum of Modern Art</a></span></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://www.idref.fr/110271300">IdRef</a></span></li></ul></div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Mount_Wilson_Observatory&oldid=1269285229">https://en.wikipedia.org/w/index.php?title=Mount_Wilson_Observatory&oldid=1269285229</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Astronomical_observatories_in_California" title="Category:Astronomical observatories in California">Astronomical observatories in California</a></li><li><a href="/wiki/Category:Educational_buildings_in_Los_Angeles_County,_California" title="Category:Educational buildings in Los Angeles County, California">Educational buildings in Los Angeles County, California</a></li><li><a href="/wiki/Category:San_Gabriel_Mountains" title="Category:San Gabriel Mountains">San Gabriel Mountains</a></li><li><a href="/wiki/Category:San_Gabriel_Mountains_National_Monument" title="Category:San Gabriel Mountains National Monument">San Gabriel Mountains National Monument</a></li><li><a href="/wiki/Category:History_of_Pasadena,_California" title="Category:History of Pasadena, California">History of Pasadena, California</a></li><li><a href="/wiki/Category:Landmarks_in_Los_Angeles" title="Category:Landmarks in Los Angeles">Landmarks in Los Angeles</a></li><li><a href="/wiki/Category:Myron_Hunt_buildings" title="Category:Myron Hunt buildings">Myron Hunt buildings</a></li><li><a href="/wiki/Category:Edwin_Hubble" title="Category:Edwin Hubble">Edwin Hubble</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Pages_using_gadget_WikiMiniAtlas" title="Category:Pages using gadget WikiMiniAtlas">Pages using gadget WikiMiniAtlas</a></li><li><a href="/wiki/Category:Webarchive_template_wayback_links" title="Category:Webarchive template wayback links">Webarchive template wayback links</a></li><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:Use_mdy_dates_from_October_2023" title="Category:Use mdy dates from October 2023">Use mdy dates from October 2023</a></li><li><a href="/wiki/Category:Coordinates_on_Wikidata" title="Category:Coordinates on Wikidata">Coordinates on Wikidata</a></li><li><a href="/wiki/Category:Articles_using_Infobox_observatory_using_locally_defined_parameters" title="Category:Articles using Infobox observatory using locally defined parameters">Articles using Infobox observatory using locally defined parameters</a></li><li><a href="/wiki/Category:Commons_category_link_from_Wikidata" title="Category:Commons category link from Wikidata">Commons category link from Wikidata</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 13 January 2025, at 23:06<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=Mount_Wilson_Observatory&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><picture><source media="(min-width: 500px)" srcset="/static/images/footer/wikimedia-button.svg" width="84" height="29"><img src="/static/images/footer/wikimedia.svg" width="25" height="25" alt="Wikimedia Foundation" lang="en" loading="lazy"></picture></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><picture><source media="(min-width: 500px)" srcset="/w/resources/assets/poweredby_mediawiki.svg" width="88" height="31"><img src="/w/resources/assets/mediawiki_compact.svg" alt="Powered by MediaWiki" width="25" height="25" loading="lazy"></picture></a></li> </ul> </footer> </div> </div> </div> <div class="vector-header-container vector-sticky-header-container"> <div id="vector-sticky-header" class="vector-sticky-header"> <div class="vector-sticky-header-start"> <div class="vector-sticky-header-icon-start vector-button-flush-left vector-button-flush-right" aria-hidden="true"> <button class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-sticky-header-search-toggle" tabindex="-1" data-event-name="ui.vector-sticky-search-form.icon"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </button> </div> <div role="search" class="vector-search-box-vue vector-search-box-show-thumbnail vector-search-box"> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail"> <form action="/w/index.php" id="vector-sticky-search-form" class="cdx-search-input cdx-search-input--has-end-button"> <div class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia"> <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <div class="vector-sticky-header-context-bar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-sticky-header-toc" class="vector-dropdown mw-portlet mw-portlet-sticky-header-toc vector-sticky-header-toc vector-button-flush-left" > <input type="checkbox" id="vector-sticky-header-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-sticky-header-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-sticky-header-toc-label" for="vector-sticky-header-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-sticky-header-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div class="vector-sticky-header-context-bar-primary" aria-hidden="true" ><span class="mw-page-title-main">Mount Wilson Observatory</span></div> </div> </div> <div class="vector-sticky-header-end" aria-hidden="true"> <div class="vector-sticky-header-icons"> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-talk-sticky-header" tabindex="-1" data-event-name="talk-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbles mw-ui-icon-wikimedia-speechBubbles"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-subject-sticky-header" tabindex="-1" data-event-name="subject-sticky-header"><span class="vector-icon mw-ui-icon-article mw-ui-icon-wikimedia-article"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-history-sticky-header" tabindex="-1" data-event-name="history-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-history mw-ui-icon-wikimedia-wikimedia-history"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only mw-watchlink" id="ca-watchstar-sticky-header" tabindex="-1" data-event-name="watch-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-star mw-ui-icon-wikimedia-wikimedia-star"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-edit-sticky-header" tabindex="-1" data-event-name="wikitext-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-wikiText mw-ui-icon-wikimedia-wikimedia-wikiText"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-ve-edit-sticky-header" tabindex="-1" data-event-name="ve-edit-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-edit mw-ui-icon-wikimedia-wikimedia-edit"></span> <span></span> </a> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only" id="ca-viewsource-sticky-header" tabindex="-1" data-event-name="ve-edit-protected-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-editLock mw-ui-icon-wikimedia-wikimedia-editLock"></span> <span></span> </a> </div> <div class="vector-sticky-header-buttons"> <button class="cdx-button cdx-button--weight-quiet mw-interlanguage-selector" id="p-lang-btn-sticky-header" tabindex="-1" data-event-name="ui.dropdown-p-lang-btn-sticky-header"><span class="vector-icon mw-ui-icon-wikimedia-language mw-ui-icon-wikimedia-wikimedia-language"></span> <span>46 languages</span> </button> <a href="#" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive" id="ca-addsection-sticky-header" tabindex="-1" data-event-name="addsection-sticky-header"><span class="vector-icon mw-ui-icon-speechBubbleAdd-progressive mw-ui-icon-wikimedia-speechBubbleAdd-progressive"></span> <span>Add topic</span> </a> </div> <div class="vector-sticky-header-icon-end"> <div class="vector-user-links"> </div> </div> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-694c756cf9-h6kc7","wgBackendResponseTime":151,"wgPageParseReport":{"limitreport":{"cputime":"0.797","walltime":"1.037","ppvisitednodes":{"value":4375,"limit":1000000},"postexpandincludesize":{"value":114321,"limit":2097152},"templateargumentsize":{"value":4444,"limit":2097152},"expansiondepth":{"value":20,"limit":100},"expensivefunctioncount":{"value":16,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":134496,"limit":5000000},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 906.287 1 -total"," 34.19% 309.827 2 Template:Infobox"," 32.47% 294.259 1 Template:Infobox_Observatory"," 25.34% 229.670 1 Template:Reflist"," 11.49% 104.139 11 Template:Cite_news"," 10.07% 91.308 1 Template:Authority_control"," 8.40% 76.110 2 Template:Short_description"," 7.74% 70.105 17 Template:Cite_web"," 7.62% 69.045 6 Template:If_first_display_both"," 6.35% 57.514 1 Template:Portal_bar"]},"scribunto":{"limitreport-timeusage":{"value":"0.519","limit":"10.000"},"limitreport-memusage":{"value":11691860,"limit":52428800}},"cachereport":{"origin":"mw-api-int.codfw.main-679bf888dd-22s4c","timestamp":"20250225120839","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Mount Wilson Observatory","url":"https:\/\/en.wikipedia.org\/wiki\/Mount_Wilson_Observatory","sameAs":"http:\/\/www.wikidata.org\/entity\/Q466863","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q466863","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2003-04-20T21:50:23Z","dateModified":"2025-01-13T23:06:43Z","image":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/2\/20\/Chara-2000-09-15.JPG","headline":"astronomical observatory in Los Angeles County, California"}</script> </body> </html>