A galactic black hole has the same mass as millions to billions of suns. It's long been thought that such black holes grow by consuming matter, including stars. But models show that it's less likely for a lone star to fall into a black hole.

(Related: "Black Hole Caught Eating a Star, Gamma-Ray Flash Hints.")

"If you want to bring a star into a black hole, you can try throwing a single star at it, but like a comet that flies past the sun, nothing of interest will happen unless you get a very nearly direct hit," explained study co-author Ben Bromley, an astrophysicist at the University of Utah.

"On the other hand, if you throw a binary at the