It may be that the center of the galaxy is the least likely place to find an extraterrestrial civilization. New findings reported in Astrophysical Journal Letters indicate the galactic core undergoes periodic eras of star formation that are caused by inflowing gas from a band of material about 500 light years away from the center. The result: massive — and (on an astronomical scale) frequent — explosions that would spew deadly radiation at any planets to be found there.

The team, led by astronomer Antony Stark of the Harvard-Smithsonian Center for Astrophysics, discovered that tidal forces and interactions with nearby stellar material cause the ring of gas to build until it reaches a critical point, at which time it collapses into the galactic center and fuels a burst of star formation. Stark believes the next starburst in the Milky Way will occur within 10 million years; life on any planets nearby would be snuffed out quickly. The Earth, at 25,000 light years from the core, is presumably exempt from danger.

Note the facility for this discovery: the 1.7 meter AST/RO telescope located at the National Science Foundation’s Amundsen-Scott Station at the South Pole — another reminder of Antarctica’s useful conditions for deep-sky observing. An earlier posting here looked at an automated station called AASTINO (Automated Site Testing International Laboratory) some 3250 meters above sea level on the Antarctic Plateau.

References: Antony A. Stark, et al, “Gas Density, Stability, and Starbursts near the Inner Lindblad Resonance of the Milky Way.” Astrophysical Journal Letters Vol. 614, Number 1, Part 2 (October 10, 2004). A press release from the Harvard-Smithsonian Center for Astrophysics can be found here.