Scientists have finally uncovered what the mysterious object at the center of the Milky Way Galaxy really is.
Since spotting years ago, astronomers believed it to be a hydrogen gas cloud drifting ever closer to the galaxy's massive black hole. Led by researchers at UCLA, a multi-institutional team discovered it to be a pair of binary stars that apparently merged to form one huge star covered in gas and dust.
Their study is published in The Astrophysical Journal Letters.
"G2 survived and continued happily on its orbit; a simple gas cloud would not have done that," study lead researcher Andrea Ghez, professor of physics and astronomy at UCLA, said in a press release. "G2 was basically unaffected by the black hole. There were no fireworks."
In addition to being a 2008 MacArthur fellow, Ghez serves as chair of the Lauren B. Leichtman and Arthur E. Levine in Astrophysics. According to the release, she studies the multitudes of objects that orbit the Milky Way's supermassive black hole.
The previously unknown object, referred to as G2, appears to be part of a larger trend in binary star pairs being joined together by the black hole's robust gravitational force. Along with the study's lead author, Gunther Witzel, a UCLA postdoctoral scholar, the researchers made their observations at Hawaii's W.M. Keck Observatory.
Ghez said G2's approach to the black hole "was one of the most watched events in astronomy in my career."
"We are seeing phenomena about black holes that you can't watch anywhere else in the universe," she said. "We are starting to understand the physics of black holes in a way that has never been possible before."
