Online Astronomy eText: Galaxies and the Universe
The M31 Deep Field
 An 84-hour Hubble Space Telescope exposure of a portion of the halo of M31. The image reveals stars and galaxies as faint as magnitude 31. Not long ago, the image of the globular cluster on the left side of the image would have been an excellent one for clusters in our own galaxy. To achieve such an image in a galaxy 2 million light years away represents a tremendous improvement in image quality. (T. M. Brown (STScI) et al., ESA, NASA, apod030519)