• 3 weeks ago
Astronomers using the Chandra X-ray Observatory and other telescopes "have determined that a giant black hole has destroyed a large star and strewn its contents into space," according to NASA.

Credit: NASA/CXC/A. Hobart
Transcript
00:00Visit Chandra's beautiful universe.
00:06Assassin 14 Li.
00:10Astronomers have made an unprecedented forensic study of a star that was torn apart when it
00:15ventured too close to a giant black hole and then had its insides tossed out into space.
00:22NASA's Chandra X-ray Observatory and ESA's XMM-Newton studied the amount of nitrogen
00:27and carbon near a black hole known to have torn apart a star.
00:32Astronomers think these elements were created inside the star before it was ripped apart
00:36as it neared the black hole.
00:38Astronomers have found many examples of tidal disruption events in recent years where the
00:42gravitational forces from a massive black hole destroy a star.
00:48This causes a flare, often seen in optical and ultraviolet light and X-rays, as the star's
00:53debris is heated up.
00:56This one, called Assassin 14 Li, A-S-A-S-S-N-dash-14-L-I, stands out for several reasons.
01:04At the time of discovery in November 2014, it was the closest tidal disruption to Earth,
01:10about 290 million light-years, in about a decade.
01:15Because of this proximity, Assassin 14 Li has provided an extraordinary level of detail
01:21about the destroyed star.
01:24The research team applied new theoretical models to make improved estimates, compared
01:28to previous work, of the amount of nitrogen and carbon around the black hole.
01:33The relative amount of nitrogen to carbon that was found points to material from the
01:37interior of a doomed star, weighing about three times the mass of the sun.
01:43This would make the star in Assassin 14 Li one of the most massive, and perhaps the most
01:48massive, that astronomers have seen ripped apart by a black hole to date.
01:54In addition to the unusual size of the destroyed star, and the ability to conduct the detailed
01:59forensics on it, Assassin 14 Li is also exciting because of what it means for future studies.
02:07Astronomers have seen moderately massive stars like Assassin 14 Li's in the star cluster
02:11containing the supermassive black hole in the center of our galaxy.
02:16Therefore, the ability to estimate stellar masses of tidally disrupted stars potentially
02:21gives astronomers a way to identify the presence of star clusters around supermassive black
02:26holes in more distant galaxies.
02:30Until this study, there was a strong possibility that the elements observed in X-rays might
02:35have come from gas released in previous eruptions from the supermassive black hole.
02:40The pattern of elements analyzed here, however, appears to have come from a single star.

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