Astronomers have discovered nearly 100 examples of massive black holes shredding and devouring stars, almost all of them where you’d expect to find massive black holes: in the star-dense cores of massive galaxies.
University of California, Berkeley, astronomers have now discovered the first instance of a massive black hole tearing apart a star thousands of light years from the galaxy’s core, which itself contains a massive black hole.
The off-center black hole, which has a mass about 1 million times that of the sun, was hiding in the outer regions of the galaxy’s central bulge, but revealed itself through bursts of light generated by the spaghettification of the star — a so-called tidal disruption event, or TDE. In a TDE, the immense gravity of a black hole tugs on a star — similar to the way the moon raises ocean tides on Earth, but a lot more violently.
“The classic location where you expect massive black holes to be in a galaxy is in the center, like our Sag A* at the center of the Milky Way,” said Yuhan Yao, a Miller Postdoctoral Fellow at UC Berkeley who is lead author of a paper about the discovery recently accepted for publication in The Astrophysical Journal Letters (ApJL). “That’s where people normally search for tidal disruption events. But this one, it’s not at the center. It’s actually about 2,600 light years away. That’s the first optically discovered off-nuclear TDE discovered.”