Messier 95 (also known as NGC 3351) is a beautiful barred spiral galaxy in the "main body" of the constellation Leo, only 2/3 of a degree from M 96. Both galaxies were discovered by Pierre Mechain in 1781, and catalogued by Charles Messier four days after their discovery.
One of the fainter Messier objects, M 95 has a visual magnitude of 9.7. It is a barred spiral of type SBb, with nearly circular arms spanning 4.4' x 3.3' of sky. Its overall appearance is quite similar to that of M 91, except that M 95 has a more pronounced spiral structure.
Messier 95 has a true diameter of over 70,000 light years, an absolute magnitude of -20.2, and a luminosity of 10 billion suns. The nucleus of the galaxy is surrounded by a ring-shaped star forming region with a diameter of approximately 2000 light years. M 95 is receding at 420 miles per second.
M 95 is a member of the M 96 subgroup of the Leo I Group. The M 96 Group's brightest members are M 95, M 96, the giant ellipticals M 105 and NGC 3377, and the lenticular system NGC 3384. The M 96 Group is extremely compact, covering 3° x 1.5° of sky. The larger Leo I Group also includes the M 65 - M 66 Galaxy Group in western Leo.
M 95 was one of the galaxies in the key Hubble Space Telescope project to determine the Hubble constant by looking for Cepheid variables within galaxies, and thereby determining their distance. The result for M 95, corrected with Hipparcos satellite's Cepheid brightness zero point, is a distance of 35.5 million light years. This is in good agreement with the value of 41 million light years for M 95's neighbor M 96, and implies a distance of about 38 million light years for all the galaxies in the Leo I group.