{"id":24909,"date":"2022-03-02T03:30:19","date_gmt":"2022-03-02T08:30:19","guid":{"rendered":"https:\/\/hobbyspace.com\/Blog\/?p=24909"},"modified":"2022-03-01T12:52:57","modified_gmt":"2022-03-01T17:52:57","slug":"eso-no-black-hole-found-in-closest-black-hole-system","status":"publish","type":"post","link":"https:\/\/hobbyspace.com\/Blog\/?p=24909","title":{"rendered":"ESO: No black hole found in “closest black hole” system"},"content":{"rendered":"

A new report from the European Southern Observatory (ESO<\/a>):<\/p>\n

\u201cClosest black hole\u201d system found to contain no black hole<\/strong><\/a><\/p>\n

\"\"<\/a>
New research using data from ESO\u2019s Very Large Telescope and Very Large Telescope Interferometer has revealed that HR 6819, previously believed to be a triple system with a black hole, is in fact a system of two stars with no black hole. The scientists, a KU Leuven-ESO team, believe they have observed this binary system in a brief moment after one of the stars sucked the atmosphere off its companion, a phenomenon often referred to as \u201cstellar vampirism\u201d. This artist\u2019s impression shows what the system might look like; it\u2019s composed of an oblate star with a disc around it (a Be \u201cvampire\u201d star; foreground) and B-type star that has been stripped of its atmosphere (background).<\/figcaption><\/figure>\n

In 2020 a team led by European Southern Observatory (ESO) astronomers reported the closest black hole to Earth, located just 1000 light-years away in the HR 6819 system. But the results of their study were contested by other researchers, including by an international team based at KU Leuven, Belgium. In a paper published today, these two teams have united to report that there is in fact no black hole in HR 6819, which is instead a \u201cvampire<\/em>\u201d two-star system in a rare and short-lived stage of its evolution.<\/p>\n

The original study on HR 6819<\/a> received significant attention from both the press and scientists. Thomas Rivinius, a Chile-based ESO astronomer and lead author on that paper, was not surprised by the astronomy community\u2019s reception to their discovery of the black hole.<\/p>\n

\u201cNot only is it normal, but it should be that results are scrutinised,<\/em>\u201d he says, \u201cand a result that makes the headlines even more so.<\/em>\u201d<\/p>\n

Rivinius and his colleagues were convinced that the best explanation for the data they had, obtained with the MPG\/ESO 2.2-metre telescope<\/a>, was that HR 6819 was a triple system, with one star orbiting a black hole every 40 days and a second star in a much wider orbit. But a study led by Julia Bodensteiner, then a PhD student at KU Leuven, Belgium, proposed a different explanation<\/a> for the same data: HR 6819 could also be a system with only two stars on a 40-day orbit and no black hole at all. This alternative scenario would require one of the stars to be \u201cstripped\u201d, meaning that, at an earlier time, it had lost a large fraction of its mass to the other star.<\/p>\n

\u201cWe had reached the limit of the existing data, so we had to turn to a different observational strategy to decide between the two scenarios proposed by the two teams<\/em>,\u201d<\/p>\n

says KU Leuven researcher Abigail Frost, who led the new study published today in Astronomy & Astrophysics<\/em>.<\/p>\n