Galactic astronomers have been puzzled by an unusual bright object in the middle of the Milky Way for decades. Until now, it had been theorized that the object was a hydrogen gas cloud being sucked in by the enormous black hole in the center of the galaxy.
UCLA astronomers announced today they believe they have solved the riddle of the anomalous object commonly known as G2.
A team of researchers led by Andrea Ghez, a professor of physics and astronomy at UCLA, determined that G2 is probably 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. They discovered this because the movement of the object is choreographed by the black hole’s powerful gravitational field. The team’s research was published Monday, November 3rd in the journal Astrophysical Journal Letters.
Latest theory on G2 — Merged binary stars
The researchers believe that it’s G2 is one of an emerging class of stars near the central black hole that are created because powerful gravitic forces force the binary stars to merge into one. In the Milky Way, massive stars typically come in pairs. The G2 star probably star suffered an abrasion to its outer layer during the forced merger, but is otherwise undamaged. When two stars near the black hole merge into one, the star expands for at least a million years before gradually returning to normal. The data suggest that G2 is in this inflated stage.
Statement from researcher
G2 survived and continued happily on its orbit after passing by the black hole; “a simple gas cloud would not have done that,” noted Ghez. “G2 was basically unaffected by the black hole. There were no fireworks.”