Midsize Black Hole Hiding In Midst Of Globular Cluster – Black Holes Can ‘Grow’ Due To Collisions

Astronomers Bulent Kiziltan of the Harvard Smithsonian Center for Astrophysics, Holger Baumgardt of Australia's University of Queensland and Abraham Loeb has just made a stunning discovery. In the middle of a globular cluster located in the southern sky some 16,700 light-years from Earth sits a black hole with 1,400 to 3.700 solar masses. This discovery accounts for mid-sized black holes that are often taken for granted due to the quest for phenomena millions of times larger than the sun.

The astronomers were able to find this midsized black hole by measuring movements of pulsars found in the middle of the cluster, The Scientific American reported. With these movements the scientists were able to detect a compact and massive object. They had no doubt that this was a black hole. Kiziltan said that intermediate-sized black holes were usually expected in the middle of globular clusters but no actual evidence was found.

The University of Queensland reported the midsized black hole discovery and said that the cluster has three million stars and measures 120 light-years and dozens of pulsars. This discovery has been insignificant for a very long time and thus there could be hope that similar masses may be hiding in many globular clusters in different regions of space.

It is a long-standing theory that stellar -mass black holes are created from the midst of stars that are much larger than the sun. When these finally dry out of nuclear fuel, the star's outer layers become weak and unable to hold the radiation. The star finally collapses and then explodes into a supernova.

After the explosion, what is left is a very small volume. Taken that a 100-solar mass star will have a radius of 180 miles, its velocity exceeds the speed of light and this results in a black hole.

Aside from discovering the midsize black hole, the team is also proposing a new way to study globular clusters without going too close. Kiziltan said that it has been very difficult to study clusters because of the many stars in one region. Also the question of how black holes form and how it got in the middle of the cluster has been raised.

Scientists explain that there are actually a number of ways to form black holes inside a cluster. Black holes could form from runaway collisions of stars; a bunch of stars found in a dense region with the heaviest starting a collision. Once a black hole has formed the star dies. Everything that is unstable around the black hole will get dragged in.