A bizarre object in the centre of the Milky Way which has puzzled astronomers for years.....
A bizarre object in the centre of the Milky Way which has puzzled astronomers for years is most likely a pair of binary stars that merged together, a new study has found.
The object, known as G2, in the centre of Milky Way was believed to be a hydrogen gas cloud headed toward our galaxy’s enormous black hole.
Having studied it during its closest aapproach to the black hole this summer, University of California, Los Angeles astronomers believe that they have solved the riddle of the object.
A team led by Andrea Ghez, professor of physics and astronomy in the UCLA College, determined that G2 is most likely a pair of binary stars that had been orbiting the black hole in tandem and merged together into an extremely large star, cloaked in gas and dust – its movements choreographed by the black hole’s powerful gravitational field.
Astronomers had figured that if G2 had been a hydrogen cloud, it could have been torn apart by the black hole, and that the resulting celestial fireworks would have dramatically changed the state of the black hole.
“G2 survived and continued happily on its orbit; a simple gas cloud would not have done that,” said Ghez, who holds the Lauren B Leichtman and Arthur E Levine Chair in Astrophysics.
“G2 was basically unaffected by the black hole. There were no fireworks,” Ghez added.
Ghez, who studies thousands of stars in the neighbourhood of the supermassive black hole, said G2 appears to be just one of an emerging class of stars near the black hole that are created because the black hole’s powerful gravity drives binary stars to merge into one.
Ghez also noted that, in our galaxy, massive stars primarily come in pairs. She said the star suffered an abrasion to its outer layer but otherwise will be fine.
The research was conducted at Hawaii’s WM Keck Observatory, which houses the world’s two largest optical and infrared telescopes.
Ghez said G2 now is undergoing what she calls a “spaghetti-fication” – a common phenomenon near black holes in which large objects become elongated.
At the same time, the gas at G2’s surface is being heated by stars around it, creating an enormous cloud of gas and dust that has shrouded most of the massive star.