In 2002, an object later named “G2” was first discovered hurtling towards the black hole at the center of our galaxy. Astronomers weren’t sure what it was, most theorizing that it was a ball of hydrogen gas. When I said “hurtling” earlier, I mean, uh, “space hurtling,” I guess. Which means that here it is, 2014, and the mysterious glow cloud has finally reached the black hole, and spun away from it.
…which also means it’s not a glow cloud at all.
“G2 survived and continues happily on its orbit; a gas cloud would not do that,” said Dr. Andrea Ghez, professor of Physics & Astronomy at UCLA. “G2 was completely unaffected by the black hole; no fireworks.”
Ghez’s team has demonstrated that G2 is actually a binary star, and the gravitational pull of the black hole has merged the two, and stretched it, in a super-technical process Ghez calls “spaghetti-fication.” (And now you know that large objects around black holes become elongated, fellas.)
G2’s orbit around the black hole takes 300 years, and the UCLA team calculates that was closest to our galactic core during this summer. There is a cloud of gas and dust at G2’s surface that has obscured most of the binary star, which could be why it was so misleading when it was initially discovered. That gas cloud has only grown more massive as it has winged its way around the black hole.
Important things to note: Dr. Ghez’s work at the W. M. Keck Observatory includes developing a technique for observing the center of the universe called “speckle imaging,” that has made it possible for astronomers to discern stars from binary stars. Through these advances they’ve learned that there are more binary stars in the universe than we thought, and when they merge, they expand for up to a million years before stabilizing.
“We are starting to understand the physics of black holes in a way that has never been possible before and is possible only at the center of the galaxy.”
Space is cool.
Via Astronomy.com