NGC 3351

Messier 95 (NGC 3351) is a barred spiral galaxy in the constellation Leo, approximately 38 million light-years away and a member of the Leo I galaxy group, which also includes M96 and M105. It was discovered by Pierre Méchain on March 20, 1781, and catalogued by Charles Messier shortly after. NGC 3351 is classified as type SBb, with a well-defined central bar and moderately wound spiral arms. The galaxy is particularly notable for a complex ring structure: a prominent inner ring of star formation encircles the central bar, and faint outer ring features are detectable in deep exposures. This ringed morphology makes M95 one of the clearest examples of a "ringed barred spiral" in Messier's catalog.

The inner star-forming ring of NGC 3351 is one of the most studied such structures in any nearby galaxy. Gas driven inward by the gravitational influence of the bar accumulates at a resonance radius, where it is compressed and triggers bursts of star formation — producing the bright, blue ring of young stellar clusters and HII regions visible in the image inset. The galaxy's very center is relatively quiescent and hosts a nuclear stellar cluster and a small supermassive black hole. In 2012, a supernova (SN 2012aw) was observed in M95, briefly reaching magnitude 12.0 and making it one of the more prominent supernovae in a nearby spiral in recent decades.

In a small telescope M95 appears as a round, faint oval with a brighter nucleus and a slight central condensation; the bar and ring structures require larger apertures and longer exposures to detect visually. This image was made in February 1996 at the Kitt Peak National Observatory 0.9-meter telescope.