Barred Spiral Galaxy M-95 is one of a bright pair of spiral galaxies, ( the other is M-96 ) in the constellation of Leo. Nearby one can find a group of three companion galaxies, NGC 3379 (M-105), NGC 3384, and NGC 3389. All are part of the Leo Galaxy Cluster. This cluster includes other bright members, like spiral galaxies M-65 and M-66, plus numerous smaller systems.
M-95 is a classic example of a barred spiral galaxy shaped like the Greek letter Theta. While the bar (middle aged stars), is like that of 'normal' barred spirals, the nearly circular spiral arms (young stars, gas, and dust), form a broken ring. These arms spring from the ends of the bar and wind slightly outward, almost touching the opposite bar and arm after a revolution of about 180 degrees. Note that the spiral arms do continue on into very faint extensions.
M-95 has an unusual starburst nuclear bulge. In the nuclear bulge there is quiescent nucleus surrounded by a ring of H-II regions that appear as three bluer knots where intense star formation is taking place. In particular, the ring-like structure of M95 has an external diameter of about 20 arc seconds, around a redder nucleus of about 2 arc seconds. There are three major complexes of H-II regions, whose high content of O stars gives a young age to the burst. Alloin & Nieto (1982) suggest that the burst is related to the existence of a radial inflow of the ring toward the nucleus, which might produce an accumulation of neutral gas, providing fuel for the star formation. The UV spectrum shows unusually strong C IV and Mg II absorption lines.
M-95 contains about 100 billion solar masses and is about 100,000 light years in diameter. It was discovered by P. Mechain in March 1781.
The Deep Sky Field Guide to Uranometria 2000:
Barred Spiral Galaxy, type SAB(r)b II; Extremely bright nucleus in a strong, smooth bar 1.4x.03 minutes with dark lanes.
Dreyer's description in the New General Catalog(NGC):
Bright, large, round, pretty gradually much brighter middle nucleus; = M95.
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George Normandin, KAS
June 29th, 2002