Astronomy Picture of the Day . ... 9.11.2007 . ... The deep exposure includes bright stars, emission nebulae , star clusters, and, of course, the famous Comet Holmes . ... The brightest star in view, Alpha Persei, is itself surrounded by a loose cluster of stars - the Alpha Per Moving Cluster - at a distance of about 600 light-years. But, at a distance of a mere 14 light-minutes bright Comet Holmes still dominates the scene with its fluorescing greenish coma and foreshortened blue tail. ...