M61

M61 is a beautiful face-on barred spiral galaxy in Virgo, about 52 million light-years from Earth. It is one of the largest galaxies in the Virgo Cluster, spanning about 100,000 light-years. M61 has an active nucleus (Seyfert type) and is classified as a starburst galaxy, with vigorous star formation particularly in its spiral arms.

Located in the southern part of the Virgo Cluster, about 8 degrees north of Gamma Virginis (Porrima). In a telescope it appears as a round, diffuse glow with a bright center. The face-on orientation means the spiral arms have low surface brightness. An 8-inch telescope under dark skies begins to show hints of spiral structure. A 12-inch or larger reveals the arms more clearly. Best observed from March through June.

Discovered by Barnabus Oriani on May 5, 1779, while tracking a comet. Charles Messier observed the same area that night but initially mistook M61 for the comet! He correctly identified it as a nebula six days later. Seven supernovae have been observed in M61, more than in almost any other galaxy.