M91, NGC 4548

M91 is a spiral galaxy of type SBb in the constellation Coma Berenices. The bar is quite conspicuous. M91 was considered the `lost' Messier object: see the discussion at the Web site of Students for the Exploration and Development of Space. M91 is a member of the Virgo Cluster of galaxies, which is the dominant cluster in our Local Supercluster and about 60 million light-years away. This CCD composite picture was taken in April 1998 at the Kitt Peak 0.9-meter telescope. The Virgo cluster also includes Messier galaxies M49, M58, M59, M60, M61, M84, M85, M86, M87, M88, M89, M90, M98, M99, and M100.