Frequent starbursts sterilize center of Milky Way

A scenario in which exploding stars kill all life within the center of our galaxy is detailed by stronomer Antony Stark (Harvard-Smithsonian Center for Astrophysics) and colleagues in the October 10, 2004, issue of The Astrophysical Journal Letters. The team’s discovery was made possible using the unique capabilities of the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO). It is the only observatory in the world able to make large-scale maps of the sky at submillimeter wavelengths. The gas for each starburst comes from a ring of material located about 500 light-years from the center of our galaxy. Gas collects there under the influence of the galactic bar — a stretched oval of stars 6,000 light-years long rotating in the middle of the Milky Way. Tidal forces and interactions with this bar cause the ring of gas to build up to higher and higher densities until it reaches a critical density or “tipping point.” At that point, the gas collapses down into the galactic center and smashes together, fueling a huge burst of star formation. “A starburst is star formation gone wild,” says Stark. The next starburst in the Milky Way is coming relatively soon, predicts Stark. “It likely will happen within the next 10 million years.”