Triangulum spiral(M33; NGC 598) A spiral (Sc) galaxy in the constellation Triangulum that is the third largest of the confirmed members of the Local Group and is about 800 kiloparsecs distant. Although it is both smaller and more distant than the Andromeda galaxy it can appear larger because it is orientated face-on to us. The spiral arms are more open than those in our own Galaxy and the nucleus is relatively small and faint. It has a large number of young population I stars.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006