M61 - NGC 4303

Messier 61 (NGC 4303) is a face-on barred spiral galaxy located approximately 52 million light-years from Earth in the constellation Virgo. It is one of the largest galaxies in the Virgo Cluster, with a diameter of about 100,000 light-years, comparable to our own Milky Way. M61 was discovered by Barnabus Oriani on May 5, 1779, on the same night Charles Messier observed the same patch of sky but mistook the galaxy for a comet he was tracking. Messier only recognized it as a nebulous object several days later. M61 is a starburst galaxy, meaning it is currently undergoing an exceptionally high rate of star formation, particularly in its nuclear region. The galaxy has a complex structure featuring a prominent bar, multiple well-defined spiral arms, and numerous HII regions where new stars are actively forming. M61 is one of the most prolific supernova-producing galaxies known. As of recent years, eight supernovae have been recorded in M61: in 1926, 1961, 1964, 1999, 2006, 2008, 2014, and 2020. This remarkable frequency of supernovae is related to the galaxy's vigorous star formation, which produces a large number of massive, short-lived stars that end their lives explosively. The galaxy has an active galactic nucleus classified as a LINER with Seyfert 2 characteristics. In amateur telescopes, M61 appears as a round, diffuse glow with a brighter center. Larger telescopes of 10 inches or more under dark skies can reveal hints of the spiral arm structure, and the galaxy responds well to long-exposure astrophotography, which brings out the intricate spiral arms and HII regions.

M61 spans approximately 100,000 light-years in diameter and is located about 52 million light-years from Earth as a prominent member of the Virgo Cluster.