Highly unlikely galaxy can be swallowed by black hole

"Is the sun's gravitational pull strong enough to create a black hole that will swallow in the whole Milky Way?" asked Jessica Banuelos, 13, an eighth-grader at West Oak Middle School in Mundelein.

"There are millions of black holes in our galaxy," said Geza Gyuk, director of astronomy at the Adler Planetarium in Chicago.

A stellar black hole is the object that's left over when a very massive star dies and collapses into itself. The resulting gravitational pull is so strong that nothing can escape from the inside, but it does not affect the objects that normally orbit nearby.

"The sun will never form a black hole," Gyuk said. "A black hole occurs only for stars whose mass is greater than about 15 solar masses."

Gyuk said there are plenty of stars that collapse and create black holes.

"While there are millions of black holes in our galaxy alone, the closest one is probably many light years away."

Could a black hole pull in other stars or the galaxy?

"The only time that a stellar black hole could swallow another star would be if they had a head-on collision…," Gyuk said, "and that would be extremely rare."

The only other option, Gyuk said, would be if a companion binary star -- one of two stars that orbit each other -- was very close to its black hole mate.

"This does happen, but is very rare," Gyuk said.

You can fly through a wormhole, see the creation of the Milky Way galaxy and witness the birth of a black hole at the Adler Planetarium's StarRider Theater movie presentation, "Black Holes: The Other Side of Infinity."

For movie times and ticket purchase information, call (312) 922-STAR or refer to the planetarium Web site, http://www.adlerplanetarium.org .