{"id":560112,"date":"2026-07-21T03:53:16","date_gmt":"2026-07-21T03:53:16","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/560112\/"},"modified":"2026-07-21T03:53:16","modified_gmt":"2026-07-21T03:53:16","slug":"astronomers-find-omega-centauris-first-stellar-mass-black-hole","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/560112\/","title":{"rendered":"Astronomers Find Omega Centauri\u2019s First Stellar-Mass Black Hole"},"content":{"rendered":"

After decades of searching, astronomers have pinpointed the first of an estimated 10,000 stellar-mass black holes thought to lurk in Omega Centauri<\/a>, the most massive stellar system<\/a> in the Milky Way found so far, with a stellar mass of 3.6 million solar masses.<\/p>\n

\"Whitaker<\/a><\/p>\n

Whitaker et al. found Omega Centauri\u2019s first stellar-mass black hole, which has a visible star companion that is shown in greater detail. Image credit: ESA \/ NASA \/ Maximilian H\u00e4berle, MPIA \/ Joseph DePasquale, STScI.<\/p>\n

Omega Centauri is located approximately 18,000 light-years<\/a> away in the constellation of Centaurus.<\/p>\n

Also known as NGC 5139, this globular cluster is about 150 light-years in diameter and 12 billion years old.<\/p>\n

Of the 200 or so globular clusters that orbit the Milky Way, Omega Centauri is the largest, containing over 10 million gravitationally bound stars.<\/p>\n

It is also the brightest globular cluster in our Galaxy, at apparent visual magnitude 3.9 it is visible to southern observers with the unaided eye.<\/p>\n

Though the astronomical community previously found<\/a> evidence with the NASA\/ESA Hubble Space Telescope that an intermediate-mass black hole lurks at the cluster\u2019s center, models suggest Omega Centauri should also contain about 10,000 smaller, stellar-mass black holes.<\/p>\n

This notable population of black holes evaded detection in previous observational studies, which used the radial velocity method or looked for radio and X-ray emission from material falling onto black holes.<\/p>\n

The new discovery features a different approach, known as astrometry, to measure very small movements of stars over time.<\/p>\n

By sifting through more than 20 years of archival data from Hubble and pulling in recent data from the NASA\/ESA\/CSA James Webb Space Telescope to further refine their astrometric measurements, University of Utah astronomer Matthew Whitaker and his colleagues located a star orbiting an invisible object so hefty that it has to be a black hole.<\/p>\n

Dubbed oMEGACat BH-2, it is the first stellar-mass black hole detected in Omega Centauri, and it has some surprising qualities.<\/p>\n

The compact object has a lower-than-expected mass and, with its visible star companion, oMEGACat BH-2 has the longest orbital period of any black hole binary system known to date.<\/p>\n

\u201cWith Hubble and Webb data, we were able to see the motion of the visible main sequence star that is part of this binary, which is about 18,000 light-years away in the dense environment of Omega Centauri,\u201d Dr. Whitaker said.<\/p>\n

\u201cThe precision of these measurements is incredible, down to a fraction of a pixel on Hubble and Webb\u2019s detectors.\u201d<\/p>\n

\u201cIt would not have been possible to find this black hole without these two space telescopes.\u201d<\/p>\n

Based on the precise data from Hubble and Webb, the astronomers could chart the star\u2019s path over 20-plus years, during its closest approach to its black hole companion when it moved the fastest across the sky.<\/p>\n

From the extensive data, they determined that the visible star orbits oMEGACat BH-2 once every 94 years, making it the longest-period black hole binary ever known.<\/p>\n

The system was probably dynamically formed, meaning the star and its black hole companion did not start out together but rather found each other in this cluster.<\/p>\n

The researchers calculated that a system like oMEGACat BH-2 will survive for less than a billion years before it is torn apart by encounters with nearby stars, a much shorter span than the age of the cluster.<\/p>\n

\u201cIt\u2019s important to understand black hole populations in globular clusters because there\u2019s uncertainty about their physics and formation,\u201d said Dr. Anil Seth, also from the University of Utah.<\/p>\n

\u201cMore specifically, understanding the process of forming black holes and then dynamically forming binaries is vital, because it affects our ability to interpret and understand gravitational wave events.\u201d<\/p>\n

\u201cEnvironments like Omega Centauri are the primary places where we think binaries are merging and creating these waves.\u201d<\/p>\n

The discovery is described in a paper<\/a> in the Astrophysical Journal Letters.<\/p>\n

_____<\/p>\n

Matthew Whitaker et al. 2026. A Long Period Stellar-mass Black Hole Binary in \u03c9 Centauri. ApJL 1006, L1; doi: 10.3847\/2041-8213\/ae7a5c<\/p>\n","protected":false},"excerpt":{"rendered":"After decades of searching, astronomers have pinpointed the first of an estimated 10,000 stellar-mass black holes thought to…\n","protected":false},"author":2,"featured_media":560113,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[11856,4130,10804,10805,200422,5621,61,60,91,236745,236746,82,247,9315,109965,129141,5623],"class_list":["post-560112","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-binary-star","tag-black-hole","tag-csa","tag-esa","tag-globular-cluster","tag-hubble","tag-ie","tag-ireland","tag-nasa","tag-omega-centauri","tag-omegacat-bh-2","tag-science","tag-space","tag-star","tag-star-cluster","tag-stellar-mass-black-hole","tag-webb"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/560112","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=560112"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/560112\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/560113"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=560112"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=560112"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=560112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}