A celestial object known as ‘G2’, believed to be a cloud of hydrogen gas was discovered by researchers in 2003. However, earlier this year, it had a close encounter with a supermassive black hole at the center of the Milky Way.
The astronomers were quite excited about this phenomenon because this would eventually enable them to see the huge gas cloud being gobbled up by the black hole called Sagittarius A*.
In contrast to what the astronomers expected, however, G2 was not smashed during its encounter with the black hole, and a recent study reveals an authentic explanation why.
Andrea Ghez from the department of physics and astronomy at the University of California, Los Angeles (UCLA), and colleagues said that, “the reason G2 proceeded intact after its encounter with the black hole is that it is not actually a cloud of hydrogen gas at all.” The study is published on 3rd November in the Astrophysical Journal Letters.
The researchers claimed that if G2 had been a hydrogen gas cloud as initially assumed, it could have been torn apart by Sagittarius A* that would have produced celestial fireworks.
Ghez said, “G2 survived and continued happily on its orbit; a simple gas cloud would not have done that. G2 was basically unaffected by the black hole. There were no fireworks.”
The researchers conducted a detailed study of G2 with the help of the world’s largest optical and infrared telescopes at the W.M. Keck Observatory in Hawaii and suggested that G2 is probably a pair of stars.
The binary star system had been orbiting the black hole together and then merged to become an extremely large star enveloped in the dust and gas with its movement being influenced by the powerful gravitational field of the black hole, Ghez and colleagues claimed.
Similarly, the researchers noted that G2 seemed to be one of a rising class of stars close to the black hole, which were created due to the powerful gravity of the black hole causing the binary stars to merge into one.
“G2 is a dusty red object linked with gas that reveals tidal interactions as it’s next to its closest approach to the Galaxy’s central black hole. We propose that G2 is a binary star merger product and will ultimately appear similar to the B-stars that are tightly clustered around the black hole (the so-called S-star cluster),” researchers wrote.
