{"id":103870,"date":"2019-09-26T08:25:54","date_gmt":"2019-09-26T18:25:54","guid":{"rendered":"https:\/\/www.hawaii.edu\/news\/?p=103870"},"modified":"2019-09-26T08:25:54","modified_gmt":"2019-09-26T18:25:54","slug":"black-hole-shreds-star","status":"publish","type":"post","link":"https:\/\/www.hawaii.edu\/news\/2019\/09\/26\/black-hole-shreds-star\/","title":{"rendered":"Black hole shreds star, <abbr title=\"University of Hawaii\">ÌÇÐÄVlog¹Ù·½<\/abbr> astronomer on discovery team"},"content":{"rendered":"<span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading time: <\/span> <span class=\"rt-time\"> 3<\/span> <span class=\"rt-label rt-postfix\">minutes<\/span><\/span><div class=\"responsive-video-wrap-post\"><figure class=\"wp-block-embed wp-block-embed-youtube is-type-video is-provider-youtube epyt-figure\"><div class=\"wp-block-embed__wrapper\"><div class=\"epyt-video-wrapper\"><iframe  id=\"_ytid_36360\"  width=\"676\" height=\"380\"  data-origwidth=\"676\" data-origheight=\"380\" src=\"https:\/\/www.youtube.com\/embed\/85tdoDt1Qh0?enablejsapi=1&origin=https:\/\/www.hawaii.edu&rel=0&autoplay=0&cc_load_policy=0&cc_lang_pref=&iv_load_policy=1&loop=0&fs=1&playsinline=0&autohide=2&theme=dark&color=red&controls=1&disablekb=0&\" class=\"__youtube_prefs__  no-lazyload\" title=\"TESS Catches its First Star-destroying Black Hole\"  allow=\"fullscreen; accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen data-no-lazy=\"1\" data-skipgform_ajax_framebjll=\"\"><\/iframe><\/div><\/div><\/figure><\/div>\n<p>For the first time, astronomers have witnessed the immediate aftermath of a star being violently ripped apart by a supermassive black hole.<\/p>\n<p>The observations were published Thursday in <em>The Astrophysical Journal<\/em>. <strong>Benjamin Shappee<\/strong> at the University of <span aria-label=\"Hawaii\">Hawai&#699;i<\/span> <a href=\"http:\/\/www.ifa.hawaii.edu\/\">Institute for Astronomy<\/a> is part of the team of astronomers led by Carnegie Observatories\u2019 Thomas Holoien. Both are founding members of the Ohio State University-based All-Sky Automated Survey for Supernovae (<abbr>ASAS-SN<\/abbr>).<\/p>\n<p>The <abbr>ASAS-SN<\/abbr> telescope network discovered the event, named <abbr>ASASSN-19bt<\/abbr>, on January 29, 2019, and quickly triggered follow-up observations from ground-based telescopes in Chile, as well as space-based X-ray and ultraviolet cameras on board <abbr title=\"National Aeronautics and Space Administration\">NASA<\/abbr>\u2019s Swift satellite. In a stroke of luck, <abbr>ASASSN-19bt<\/abbr> occurred in the exact patch of sky that <abbr>NASA<\/abbr>\u2019s planet-hunting Transiting Exoplanet Survey Satellite (<abbr>TESS<\/abbr>)\u00a0was monitoring, allowing astronomers to capture images of the event every 30 minutes for months, including during the first moments.<\/p>\n<p>Known as tidal disruption events, or <abbr>TDE<\/abbr>s, these occur when a star gets too close to a supermassive black hole, like those thought to lie at the center of most large galaxies. The black hole\u2019s immense gravity overwhelms the star\u2019s own gravity, and tears it to shreds. Some of this material is flung out into space, while the rest falls back onto the black hole, forming a disk of hot, bright gas as it is consumed. By observing the light given off during this process, which increases until it reaches a peak brightness and then tapers off, astronomers can better understand the physics of the black hole and the forces driving these phenomena. But first, they have to be discovered.<\/p>\n<p>&ldquo;When you don\u2019t know where or when something will happen, you have to look everywhere all the time. This is exactly what <abbr>ASAS-SN<\/abbr> tries to do,&rdquo; explained Shappee.<\/p>\n<p><abbr>ASAS-SN<\/abbr> is a network of 20 robotic telescopes distributed around the world, including one on Haleakal\u0101 on Maui. <abbr>ASAS-SN<\/abbr> monitors the entire visible northern and southern skies every 20 hours. This unique capability allows astronomers to look for explosive events nearly everywhere, nearly all the time. The project\u2019s camera in South Africa recorded the changing brightness of an object and sent out an automated alert. Within a day, the team classified <abbr>ASASSN-19bt<\/abbr> as a rare type of event &#8211; the tidal disruption of a star by a supermassive black hole.<\/p>\n<p>Jumping into action, the team requested follow-up observations at X-ray and ultraviolet wavelengths using <abbr>NASA<\/abbr>\u2019s Swift telescope, <abbr>ESA<\/abbr>\u2019s (European Space Agency\u2019s) <abbr>XMM<\/abbr>-Newton observatory, ground-based 1-meter telescopes in the global Las Cumbres Observatory network, and a number of other ground-based observatories. Together with the <abbr>TESS<\/abbr> data, these observations paint a picture of a tidal disruption event in unprecedented detail.<\/p>\n<p>&ldquo;Only a handful of <abbr>TDE<\/abbr>s have been discovered before they reached peak brightness, and this one was found just a few days after it started to brighten. And thanks to being in <abbr>TESS<\/abbr>\u2019 Continuous Viewing Zone, we have observations of it every 30 minutes going back months\u2014more than ever before possible for one of these events,&rdquo; said Holoien. &ldquo;This makes <abbr>ASASSN-19bt<\/abbr> the new poster child for <abbr>TDE<\/abbr> research.&rdquo;<\/p>\n<p>The team was able to follow the <abbr>TDE<\/abbr>\u2019s evolution from 42 days before its peak brightness, by finding it in <abbr>TESS<\/abbr> data taken before the event was discovered by <abbr>ASAS-SN<\/abbr>. \u201cThe images that <abbr>TESS<\/abbr> is taking can only be downloaded to Earth every two weeks, which is why we intensively monitor the <abbr>TESS<\/abbr> field with <abbr>ASAS-SN<\/abbr> from the ground.\u201d added Holoien.<\/p>\n<p><abbr>ASASSN-19bt<\/abbr> turns out to be unique in several ways. Its host galaxy is younger and more dust-filled than those of other previously observed <abbr>TDE<\/abbr>s. The early discovery and quick follow-up observations by the <abbr>ASAS-SN<\/abbr> team caught a short, rapid cooling event that lasted for two days in the first Swift observations, after which its temperature leveled off and its luminosity continued to build toward its peak. The increase in brightness as <abbr>ASASSN-19bt<\/abbr> approached its peak was extremely smooth with very little variation; a new piece of information about <abbr>TDE<\/abbr>s revealed only by the <abbr>TESS<\/abbr> data that enabled researchers to see such detail. These revelations will improve astronomers\u2019 ability to identify <abbr>TDE<\/abbr>s and differentiate them from other celestial events whose emission is much more variable.<\/p>\n<p>&ldquo;The excitement is likely to keep coming.&rdquo; remarked Shappee, describing three initiatives that will intensify research in <span aria-label=\"Hawaii\">Hawai&#699;i<\/span> for the explosive, violent event that will be observed by <abbr>TESS<\/abbr>.\u00a0First, <abbr>ASAS-SN<\/abbr> will revisit the parts of the sky that <abbr>TESS<\/abbr> is observing more frequently&#8212;four times per day&#8212;thanks to funding from a <abbr title=\"Mount\">Mt.<\/abbr> Cuba Astronomical Foundation grant. Second, On July 18, 2019 <abbr>TESS<\/abbr> began its second year of observations, and is now observing regions of the sky where telescopes in <span aria-label=\"Hawaii\">Hawai&#699;i<\/span> are well positioned to observe interesting objects seen by <abbr>TESS<\/abbr>. Third, Shappee and his team were just awarded a $200,000 grant, &ldquo;Using <abbr>TESS<\/abbr> as a Transient Explorer Survey Telescope,&rdquo; which will strengthen the partnerships between <abbr>TESS<\/abbr> and the telescopes on Maunakea and Haleakal\u0101.<\/p>\n<figure id=\"attachment_103876\" aria-describedby=\"caption-attachment-103876\" style=\"width: 676px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2019\/09\/black_hole_star_shred.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2019\/09\/black_hole_star_shred.jpg\" alt=\"black hole renderin\" width=\"676\" height=\"381\" class=\"size-full wp-image-103876\" srcset=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2019\/09\/black_hole_star_shred.jpg 676w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2019\/09\/black_hole_star_shred-130x73.jpg 130w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2019\/09\/black_hole_star_shred-300x169.jpg 300w\" sizes=\"auto, (max-width: 676px) 100vw, 676px\" \/><\/a><figcaption id=\"caption-attachment-103876\" class=\"wp-caption-text\">After passing too close to a supermassive black hole, the star in this artist&#8217;s conception is torn apart into a thin stream of gas, which is then pulled back around the black hole and slams into itself, creating a bright shock and ejecting more hot material. Illustration by Robin Dienel courtesy of the Carnegie Institution for Science<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>For the first time, astronomers have witnessed the immediate aftermath of a star being violently ripped apart by a supermassive black hole.<\/p>\n","protected":false},"author":16,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30],"tags":[34,35,1363,9],"class_list":["post-103870","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research","tag-astronomy","tag-institute-for-astronomy","tag-manoa-research","tag-uh-manoa","entry","has-media"],"aioseo_notices":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/103870","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/comments?post=103870"}],"version-history":[{"count":6,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/103870\/revisions"}],"predecessor-version":[{"id":103926,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/103870\/revisions\/103926"}],"wp:attachment":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/media?parent=103870"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/categories?post=103870"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/tags?post=103870"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}