Messier 61 — Galaxy in Virgo

M61 (NGC 4303) is a face-on barred spiral galaxy in the constellation Virgo, located approximately 52.5 million light-years from Earth. It shines at magnitude 9.7 and spans about 6.5 by 5.8 arcminutes, giving it a true diameter of roughly 100,000 light-years. M61 is classified as type SABbc — an intermediate barred spiral with loosely wound arms. It is one of the largest galaxies in the Virgo Cluster and is remarkably active in star formation, with numerous bright HII regions and young blue star clusters visible in photographs. The galaxy hosts an active nucleus classified as a Seyfert 2/LINER. M61 holds the distinction of being one of the most prolific supernova producers among known galaxies, with eight supernovae observed since 1926.

Located in the southern part of the Virgo Cluster, about 1.5 degrees north-northeast of the star 16 Virginis. M61 can be tricky to find due to its relatively low surface brightness. In binoculars it appears as a faint, round smudge. A 4-inch telescope at 80-100x shows a diffuse round glow with a slightly brighter center — its face-on orientation spreads the light over a larger area, making it appear fainter than its magnitude suggests. An 8-inch telescope under dark skies begins to reveal some mottled structure, and larger apertures (12 inches+) can trace the spiral arms. Best observed from March through June.

Discovered by Barnabus Oriani on May 5, 1779, while observing a comet. Charles Messier independently found it the same night but initially confused it with the comet. Eight supernovae have been observed in M61: in 1926, 1961, 1964, 1999, 2006, 2008, 2014, and 2020 — making it one of the most prolific supernova-hosting galaxies known. The most recent, SN 2020jfo, was a Type II supernova.