Variable Stars in a Distant Spiral Galaxy ,1999.

NASA Hubble Space Telescope (HST) view of the magnificent spiral galaxy NGC 4603, the most distant galaxy in which a special clas of pulsating stars called Cepheid variables have been found. It is asociated with the Centaurus cluster, one of the most masive asemblages of galaxies in the nearby universe. The Local Group of galaxies, of which the Milky Way is a member, is moving in the direction of Centaurus at a speed of more than a million miles an hour under the influence of the gravitational pull of the matter in that direction. Clusters of young bright blue stars highlight the galaxy's spiral arms. In contrast, red giant stars in the proces of dying are also found.