Astronomers discover a rare black hole in Cigar Galaxy

Updated: Sep 19, 2014, 16:08 PM IST
Astronomers discover a rare black hole in Cigar Galaxy

Pooja Bhula tells you about what makes the black hole discovered in Cigar Galaxy interesting and some fun facts about the this astronomical phenomenon

As per a recent ANI report, a team of astronomers from University of Maryland has succeeded in accurately measuring and thus confirming the existence of a black hole about 400 times the mass of our sun in Cigar Galaxy (M82). Moreover, Richard Mushotzky–a UMD astronomy professor, and Tod Strohmayer–co-author of NASA’s Goddard Space Flight Center, had suspected the existence of an intermediate black hole in M82 for a decade, but at that time estimates of its mass were not definitive enough to confirm it. How has it been confirmed? In 1999, a NASA satellite telescope detected x-rays, which were dubbed M82 X-1; post that they were observed 800 times between 2004 and 2010 through NASA’s RXTE (Rossi X-Ray Timing Explorer ) satellite telescope.

Why is this discovery important?

"Until about 15 years ago, black holes were merely a theoretical phenomenon. We've only recently found evidence to prove their existence and that too in very few galaxies, one being our Milky Way. This particular discovery is very interesting because while scientist believed there were supermassive black holes (millions or billion times the sun's mass), and very small ones (10-15 times the sun's mass), intermediate-sized black holes were considered non-existent. It's also exciting to know that unlike the supermassive black holes, this one is not in the centre of the galaxy," says Arvind Paranjpye, Director of Nehru Planetarium.


Black holes are born from stars

Stars die in different ways, some continue giving light till the end, some expand, oscillate and shrink, and some keep expanding till they explode. Once a star expands to 10 or more times the mass of the sun, its gravitational pull is so strong that it devours everything around it. But black holes are not a common occurance, only a small fraction of stars have this fate.

Light can't pass through black holes

If an object is thrown with such a force that it goes up at 11.2 km/sec or more, it will be able to beat the planet's gravitational pull and leave earth. This speed is called escape velocity, and Jupiter's is much higher. A black hole is fascinating because even light, which nothing travels faster than, cannot escape its formidable gravitational pull. Isn't it marvellous how a star, which emits light, turns into a phenomenon, possibly the only one, that can swallow light.

Black holes can bend light

When light nears a black hole, but is still at a distance where the black hole's pull is not powerful enough to consume it, light (known to be linear) can still be bent by a black hole, which can also change its direction. According to NASA, black holes can also spur the growth of stars.