{"id":798114,"date":"2025-09-10T05:28:27","date_gmt":"2025-09-10T10:28:27","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=798114"},"modified":"2025-09-10T05:28:27","modified_gmt":"2025-09-10T10:28:27","slug":"mysterious-gamma-ray-burst-is-unlike-any-detected-before","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=798114","title":{"rendered":"Mysterious gamma-ray burst is unlike any detected before"},"content":{"rendered":"<p> <br \/>\n<\/p>\n<div>\n<p><iframe loading=\"lazy\" title=\"Zooming into an unusually long and repeating explosion\" width=\"1110\" height=\"624\" src=\"https:\/\/www.youtube.com\/embed\/tM6kpduH76w?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><br \/><em>This video zooms in on the gamma-ray burst GRB 250702B, a powerful explosion that repeated several times over the course of a day on July 2, 2025. It\u2019s an event unlike anything we\u2019ve witnessed before. It took place in another galaxy, but its cause remains unknown. Video via ESO\/ L. Cal\u00e7ada\/ N. Risinger (skysurvey.org)\/ Digitized Sky Survey 2\/ VISTA Hemisphere Survey\/ A. Levan, A. Martin-Carrillo et al. Music: Azul Cobalto.<\/em><\/p>\n<ul>\n<li><strong>Astronomers have spotted a mysterious gamma-ray burst.<\/strong> It\u2019s unlike any we\u2019ve detected before.<\/li>\n<li><strong>Most gamma-ray bursts last just minutes at the most.<\/strong> They occur when a massive star dies or is ripped apart.<\/li>\n<li><strong>But this gamma-ray burst lasted for a day.<\/strong> That\u2019s unprecedented. So what was the source of this mysterious gamma-ray burst?<\/li>\n<\/ul>\n<p>ESO published this original story on September 9, 2025. Edits by EarthSky.<\/p>\n<h3>Mysterious gamma-ray burst is unlike any detected before<\/h3>\n<p>Astronomers have detected an explosion of gamma rays that repeated several times over the course of a day, an event unlike anything we\u2019ve witnessed before. The source of the powerful radiation was outside our galaxy, its location pinpointed by the European Southern Observatory\u2019s Very Large Telescope (VLT). Gamma-ray bursts are the most powerful explosions in the universe, normally caused by the catastrophic destruction of stars. But no known scenario can completely explain this new gamma-ray burst, whose true nature remains a mystery.<\/p>\n<p>Antonio Martin-Carrillo, an astronomer at University College Dublin in Ireland is the co-lead author of a study on this signal, published in <em>The Astrophysical Journal Letters<\/em> on August 29, 2025. Martin-Carrillo said this gamma-ray burst is: <\/p>\n<blockquote>\n<p>unlike any other seen in 50 years of gamma-ray burst observations. <\/p>\n<\/blockquote>\n<figure id=\"attachment_521296\" aria-describedby=\"caption-attachment-521296\" style=\"width: 800px\" class=\"wp-caption alignnone\"><figcaption id=\"caption-attachment-521296\" class=\"wp-caption-text\">The orange dot at the center of this image is a gamma-ray burst that repeated several times over the course of a day. It\u2019s unlike anything we\u2019ve witnessed before. ESO\u2019s Very Large Telescope (VLT) allowed astronomers to determine that the explosion didn\u2019t take place in the Milky Way but in another galaxy.\u00a0Astronomers first spotted this gamma-ray burst \u2013 GRB 250702B \u2013 on July 2, 2025. The image shown here is from July 3. Image via ESO\/ A. Levan, A. Martin-Carrillo et al.<\/figcaption><\/figure>\n<h3>A one-of-a-kind gamma-ray burst<\/h3>\n<p>Gamma-ray bursts are the most energetic explosions in the universe. Catastrophic events \u2013 like massive stars dying in powerful blasts or black holes ripping apart stars \u2013 can produce gamma-ray bursts. They usually last milliseconds to minutes. But this signal \u2013 GRB 250702B \u2013 lasted about a day. Andrew Levan, astronomer at Radboud University, The Netherlands, and co-lead author of the study, said: <\/p>\n<blockquote>\n<p>This is 100 to 1,000 times longer than most gamma-ray bursts.  <\/p>\n<\/blockquote>\n<p>Martin-Carrillo added:<\/p>\n<blockquote>\n<p>More importantly, gamma-ray bursts never repeat since the event that produces them is catastrophic.<\/p>\n<\/blockquote>\n<p>The initial alert about this gamma-ray burst came on July 2, 2025, from NASA\u2019s Fermi Gamma-ray Space Telescope. Fermi detected not one but three bursts from this source over the course of several hours. Retrospectively, astronomers also discovered the source had been active almost a day earlier. The Einstein Probe \u2013 an X-ray space telescope mission by the Chinese Academy of Sciences with the European Space Agency (ESA) and the Max Planck Institute for Extraterrestrial Physics \u2013 made these earlier observations. It\u2019s the first time such a long and repeating gamma-ray burst has been seen. <\/p>\n<p>These observations only provided an approximate location for the gamma-ray burst. And that location was toward the plane of our galaxy, crowded with stars. Therefore, the team turned to ESO\u2019s VLT to pinpoint the actual source within this area. Levan said: <\/p>\n<blockquote>\n<p>Before these observations, the general feeling in the community was that this gamma-ray burst must have originated from within our galaxy. The VLT fundamentally changed that paradigm. <\/p>\n<\/blockquote>\n<h3>Pinpointing the mysterious gamma-ray burst<\/h3>\n<p>Using the VLT\u2019s HAWK-I camera, they found evidence that the source may actually reside in another galaxy. This was later confirmed by the NASA\/ESA Hubble Space Telescope. Martin-Carrillo said: <\/p>\n<blockquote>\n<p>What we found was considerably more exciting: the fact that this object is extragalactic means that it is considerably more powerful.<\/p>\n<\/blockquote>\n<p>The size and brightness of the host galaxy suggest it may lie a few billion light-years away. But scientists will need more data to refine this distance. <\/p>\n<h3>Why did it occur?<\/h3>\n<p>The nature of the event that caused this gamma-ray burst is still unknown. One possible scenario is a massive star collapsing onto itself, releasing vast amounts of energy in the process. Levan said: <\/p>\n<blockquote>\n<p>If this is a massive star, it is a collapse unlike anything we have ever witnessed before.<\/p>\n<\/blockquote>\n<p>That\u2019s because the gamma-ray burst from a massive star collapse would have lasted just a few seconds. Alternatively, a star being ripped apart by a black hole could produce a day-long gamma-ray burst. But to explain other properties of the explosion would require an unusual star being destroyed by an even more unusual black hole.<\/p>\n<p>To learn more about this gamma-ray burst, the team has been monitoring the aftermath of the explosion with different telescopes and instruments, including the VLT\u2019s X-shooter spectrograph and the James Webb Space Telescope. Finding that this explosion took place in another galaxy will be key to deciphering what caused it. Martin-Carrillo said: <\/p>\n<blockquote>\n<p>We are still not sure what produced this, but with this research we have made a huge step forward toward understanding this extremely unusual and exciting object. <\/p>\n<\/blockquote>\n<p>Bottom line: Astronomers have spotted a mysterious gamma-ray burst that lasted for a day. So far, all other gamma-ray bursts astronomers have seen have lasted a few minutes at most. What caused this unique event?<\/p>\n<p>Source: The Day-long, Repeating GRB 250702B: A Unique Extragalactic Transient<\/p>\n<p>Via ESO<\/p>\n<p><span class=\"cp-load-after-post\"\/><\/div>\n<div>\n<div class=\"post-author\">\n<h4>EarthSky Voices<\/h4>\n<p>                    View Articles\n                  <\/p><\/div>\n<div class=\"post-tags\">\n<h6 data-udy-fe=\"text_7c58270d\">About the Author:<\/h6>\n<p>Members of the EarthSky community &#8211; including scientists, as well as science and nature writers from across the globe &#8211; weigh in on what&#8217;s important to them.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<p><br \/>\n<br \/><a href=\"https:\/\/earthsky.org\/space\/mysterious-gamma-ray-burst-day-long-grb-250702b\/?rand=772280\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>This video zooms in on the gamma-ray burst GRB 250702B, a powerful explosion that repeated several times over the course of a day on July 2, 2025. It\u2019s an event&hellip; <\/p>\n","protected":false},"author":1,"featured_media":798115,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-798114","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth-sky"],"_links":{"self":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/798114","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=798114"}],"version-history":[{"count":0,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/798114\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/media\/798115"}],"wp:attachment":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=798114"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=798114"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=798114"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}