Black holes get a bad rap. We tend to think of them as destructive, all encompassing destroyers of stuff, consuming all in their way to add to their own bloated mass. Okay maybe I'm being a wee bit dramatic, but that's the kind of pop culture picture of one, right? Scientists have also wondered if it's even possible to create stars close to a supermassive black hole. Now, we have evidence that it is possible, and it's happening in the center of our Galaxy.
PICTURES: Probing a Spinning Black Hole
Astronomers have a rough idea of how stars form, even though many of the details are still open questions. A region of interstellar gas gets dense enough through some process to begin forming a star. The material surrounding a black hole, however, suffers intense shearing forces from rotating around such a dense object. It is hard to imagine how a clump of gas could hold itself together in such close proximity to a gravitational behemoth.
Nevertheless, evidence of star formation has been detected within two light-years of the supermassive black hole at the center of the Milky Way Galaxy, affectionately known as Sagittarius A* (pronounced "A-star," abbreviated Sgr A*). Using the fledgling Atacama Large Millimeter/Submillimeter Array (ALMA) when it was just 12 antennas and the Combined Array for Millimeter-Wave Astronomy (CARMA), a group of astronomers led by Farhad Yusef-Zadeh of Northwestern University detected emission of silicon monoxide (SiO) near the supermassive black hole.