Friday, May 27, 2011
Spitzer Sees Crystal Rain in Infant Star Outer Clouds
Tiny crystals of a green mineral called olivine are falling down like rain on a burgeoning star, according to observations from NASA's Spitzer Space Telescope. This is the first time such crystals have been observed in the dusty clouds of gas that collapse around forming stars. Astronomers are still debating how the crystals got there, but the most likely culprits are jets of gas blasting away from the embryonic star.
You need temperatures as hot as lava to make these crystals, said Tom Megeath of the University of Toledo in Ohio. He is the principal investigator of the research and the second author of a new study appearing in Astrophysical Journal Letters. "We propose that the crystals were cooked up near the surface of the forming star, and then carried up into the surrounding cloud where temperatures are much colder, and ultimately fell down again like glitter."
Spitzer's infrared detectors spotted the crystal rain around a distant, sun-like embryonic star, or protostar, referred to as HOPS-68, in the constellation Orion. The Spitzer observations were made before it used up its liquid coolant in May 2009 and began its warm mission.