From San Diego, at a meeting of the American Astronomical Society
New observations of one of the sun's brightest neighboring stars show that the debris disk surrounding it contains much fine dust, probably from recent collisions between massive objects near the star.
Using the orbiting Spitzer Infrared Observatory, Kate Y.L. Su of the University of Arizona in Tucson and her colleagues found evidence for huge amounts of microscopic dust around the star, named Vega. Because radiation from any star such as Vega quickly clears away such particles, Su's team concludes that the dust must have been produced by recent collisions. In particular, the researchers propose that two or more Pluto-size objects collided sometime in the past million years and that many subsequent collisions between the resulting fragments led to the disk around Vega.