About the Object:

The Triangulum Galaxy is the third largest galaxy in our MilkyWay’s local group of galaxies after Andromeda and the Milky Way itself. It is about three million light years away, just a bit farther than Andromeda, and is about half the size of our own Milky Way. It gets its name from the triangle shaped constellation in which it lies. One of the most interesting parts of M33 is its high rate of star formation. In this image, the most prominent star forming regions can be seen as red or pink areas. The color comes from ionized hydrogen gas that is made to fluoresce by the ultraviolet light coming from the new, hot stars. M33 is undergoing star formation at a rate roughly ten times higher than Andromeda.

Due to its relative proximity, M33 can fill the field of view of even a moderate aperture telescope, and it is a favorite subject for professionals and amateurs alike since it is possible to distinguish a large number of individual stars within the galaxy rather than just nebulosity from stars that are too far away to resolve. In fact, in a recent mosaic of images from the Hubble Space telescope, scientists were able to resolve twenty-five million individual stars in a region of space only 14,000 lightyears across. M33, like Andromeda, appears to be headed straight for the Milky Way galaxy, and the three galaxies may, in fact collide together in approximately four billion years.