Discovered by William Herschel in 1784.
NGC 7331, the large galaxy in the image above, is the dominant member of the Deer Lick Group of galaxies located in the constellation Pegasus appproximately 40 million light years from the Earth. The Deer Lick Group consists of NGC 7331 and the four small galaxies on its left. These small galaxies are actually background galaxies approximately 10 time more distent. The allignment of these galaxies with NGC 7331 is by mere chance. NGC 7331 is among 18 galaxies included in the Hubble Extragalactic Distance Scale Key Project. Cepheid variable stars were observed in these galaxies to determine the age, size and fate of the Universe.