NASA | MSFC | SOA | Chandra X-ray Observatory | 2020 Apr 23
Data from NASA's Chandra X-ray Observatory and ESA's XMM-Newton indicate that a star survived a close call with a black hole, as described in our latest press release. As a red giant star approached a supermassive black hole in the galaxy GSN 069, it was caught in the black hole's gravity. Once captured, the outer layers of the red giant containing hydrogen were stripped off and careened toward the black hole, leaving the core of the star — known as a white dwarf — behind.
The white dwarf is now in a highly elliptical orbit that completes one cycle about once every 9 hours. As its nearest point in its oval-shaped path, the white dwarf is no more than 15 times the radius of the event horizon — the point of no return — away from the black hole. This artist's illustration shows the white dwarf (on the left) when it is nearing the point of closest approach, and is being stretched by the strong gravity of the black hole (on the far right). The white dwarf should be travelling at a noticeable fraction of the speed of light at this point. At closest approach the black hole pulls material from the white dwarf into an encircling disk. This transfer releases a burst of X-rays that Chandra and XMM-Newton can detect every 9 hours. The inset is a time-lapse of Chandra data taken over a period of about 20 hours on February 14 and 15, 2019, centered on the X-ray source in the middle of GSN 069. The sequence loops to show that the X-ray brightness of the source changes regularly and dramatically over the Chandra observation. The black hole and white dwarf pair should also emit gravitational waves, especially at their nearest point. ...
GSN 069 — A Tidal Disruption Near-Miss ~ Andrew King
- Monthly Notices of the RAS: Letters 493(1):L120 (Mar 2020) DOI: 10.1093/mnrasl/slaa020
- arXiv.org > astro-ph > arXiv:2002.00970 > 03 Feb 2020
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