Messier 58 — Galaxy in Virgo

M58 (NGC 4579) is a barred spiral galaxy in the constellation Virgo, located approximately 62 million light-years from Earth in the Virgo Cluster of galaxies. It shines at magnitude 9.7 and spans about 5.5 by 4.5 arcminutes, corresponding to a true diameter of roughly 100,000 light-years — comparable in size to the Milky Way. M58 is classified as type SBb, featuring a prominent central bar structure with well-developed spiral arms winding outward. The galaxy hosts an active galactic nucleus (AGN) classified as a low-luminosity Seyfert 1.9, powered by a supermassive black hole of about 70 million solar masses. M58 is one of the brightest barred spirals in the Virgo Cluster and one of only four barred spirals in the entire Messier catalog.

Located in the heart of the Virgo Cluster, about 3.5 degrees northwest of the star Rho Virginis. Finding M58 requires careful star-hopping through the rich galaxy fields of the Virgo Cluster. In binoculars it appears as a faint, small smudge. A 4-inch telescope at 80-100x shows a small oval glow with a brighter nucleus. An 8-inch telescope reveals a larger halo around the bright core, and under excellent conditions hints of the bar structure may be glimpsed. The galaxy lies in the same field as several other Messier galaxies (M59, M60), making for a rewarding tour of the Virgo Cluster. Best observed from March through June.

Discovered by Charles Messier on April 15, 1779, on the same night he found several other Virgo Cluster galaxies. Messier described it as a 'very faint nebula.' Two supernovae have been observed in M58: SN 1988A (Type II) and SN 1989M (Type Ia). The Type Ia supernova SN 1989M was particularly well-studied and contributed to calibrating the luminosity of Type Ia supernovae as standard candles for measuring cosmic distances.