{"id":417,"date":"2024-08-29T21:33:13","date_gmt":"2024-08-29T21:33:13","guid":{"rendered":"https:\/\/as.vanderbilt.edu\/newmath2025\/?p=417"},"modified":"2025-03-11T20:52:25","modified_gmt":"2025-03-11T20:52:25","slug":"august-29-2024-the-black-hole-photon-ring","status":"publish","type":"post","link":"https:\/\/as.vanderbilt.edu\/math\/2024\/08\/29\/august-29-2024-the-black-hole-photon-ring\/","title":{"rendered":"Colloquium &#8211; The Black Hole Photon Ring: August 29, 2024"},"content":{"rendered":"<p><strong><span class=\"datetime\">August 29, 2024 (Thursday), 4:10 pm<\/span><\/strong><\/p>\n<div class=\"entry-summary\">\n<p>Alex Lupsasca &#8211; Vanderbilt University<\/p>\n<p>What does a black hole look like? The first images of the supermassive black hole M87* display a bright ring encircling the event horizon, which appears as a dark patch in its surrounding emission. But Einstein\u2019s theory of general relativity predicts that within this image there also lies a thin \u201cphoton ring\u201d consisting of multiple mirror images of the main emission. These images arise from photons that orbited around the black hole multiple times, probing the warped space-time geometry just outside its horizon. The photon ring carries an imprint of the strong gravity in this region and encodes fundamental properties of the black hole. A measurement of this predicted (but not yet observed) ring could provide a precise test of general relativity and will be one of the main targets of a NASA mission proposed to fly within the next decade: the Black Hole Explorer (BHEX).<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>August 29, 2024 (Thursday), 4:10 pm Alex Lupsasca &#8211; Vanderbilt University What does a black hole look like? The first images of the supermassive black hole M87* display a bright ring encircling the event horizon, which appears as a dark patch in its surrounding emission. But Einstein\u2019s theory of general relativity predicts that within this&#8230;<\/p>\n","protected":false},"author":74,"featured_media":754,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[7],"tags":[],"acf":[],"jetpack_featured_media_url":"https:\/\/as.vanderbilt.edu\/math\/wp-content\/uploads\/sites\/69\/2024\/08\/colloquium.png","_links":{"self":[{"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/posts\/417"}],"collection":[{"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/users\/74"}],"replies":[{"embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/comments?post=417"}],"version-history":[{"count":3,"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/posts\/417\/revisions"}],"predecessor-version":[{"id":670,"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/posts\/417\/revisions\/670"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/media\/754"}],"wp:attachment":[{"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/media?parent=417"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/categories?post=417"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/math\/wp-json\/wp\/v2\/tags?post=417"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}