Triangulum and Andromeda galaxies. Optical image of the spiral galaxies Andromeda (M31,upper right) and Triangulum (M33,lower left),separated by the red giant star Mirach (Beta Andromedae,centre). M31,the largest of the Local Group of galaxies,is around 2.5 million light years distant. It contains hundreds of billions of stars. M33,also part of the Local Group,is some 3 million light years distant,and contains some 40 billion stars. Mirach,part of the constellation of Andromeda,is around 200 light years distant |