Scientists spot supermassive black hole

Astronomers have discovered a black hole in the Milky Way so huge that it challenges existing models of how stars evolve, researchers said on November 27.

Called LB-1, this black hole is 15,000 light years from Earth and has a mass 70 times greater than the Sun, according to the journal Nature.

The Milky Way is estimated to contain 100 million stellar black holes but LB-1 is twice as massive as anything scientists thought possible, said Liu Jifeng, a National Astronomical Observatory of China professor who led the research. “Black holes of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution,” he said.

What is a black hole?

A black hole is born when a large star collapses in on itself. Far from being a “hole”, they are instead incredibly dense objects with a gravitational pull so strong that nothing, not even light, may escape them. As they suck in matter such as gas, dust and space debris, they form an accretion disk — a churning mass of super-accelerated particles that are among the brightest objects in the Universe — around them.

Scientists generally believe that there are two types of black holes. The more common stellar black holes — up to 20 times more massive than the Sun — form when the centre of a very big star collapses in on itself.

Supermassive black holes are at least a million times bigger than the Sun and their origins are uncertain.

But researchers believed that typical stars in the Milky Way shed most of their gas through stellar winds, preventing the emergence of a black hole the size of LB-1, Liu said. “Now theorists will have to take up the challenge of explaining its formation,” he said in a statement.

LB-1 was discovered by an international team of scientists using China’s sophisticated LAMOST telescope. Additional images from two of the world’s largest optical telescopes — Spain’s Gran Telescopio Canarias and the Keck I telescope in the US — confirmed that the size of LB-1, which the National Astronomical Observatory of China said was “nothing short of fantastic”.

Astronomers are still only beginning to grasp “the abundance of black holes and the mechanisms by which they form,” David Reitze, a physicist at the California Institute of Technology who was not involved in the discovery, said.

“LB-1’s large mass falls into a range known as the ‘pair instability gap’ where supernova should not have produced it. That means that this is a new kind of a black hole, formed by another physical mechanism,” Reitze said.

Manorama Yearbook app is now available on Google Play Store and iOS App Store