A new research indicates that when two galaxies collide, it causes the black holes at their cores to spiral toward each other, merge, then go on a rampage of star-eating.
The merger kicks the resulting monster black hole into surrounding stars. There, the black hole shreds and swallows stars at a rapid clip.
The research by Nick Stone and Avi Loeb suggests that an upcoming sky survey might offer astronomers a way to catch a gorging black hole “in the act”.
“Essentially, the black hole can go from starving to enjoying an all-you-can-eat buffet,” said Stone.
When tidal forces rip a star apart, its remains will spiral around the black hole, smashing and rubbing together, heating up enough to shine in the ultraviolet or X-rays. The black hole will glow as brightly as an exploding star, or supernova, before gradually fading in a distinctive way.