M58 is a magnitude +9.8 barred spiral galaxy that's one of the brightest members of the famous Virgo cluster. At a distance of 68 million light-years and despite being one of the furthest objects in the Messier catalogue it's bright enough to be visible in large binoculars and small telescopes. Although unknown when discovered, M58 was the most distant known object of all at that time. It's best seen during the months of March, April and May.
The centre of the Virgo cluster is positioned approx. halfway along a line connecting Denebola (β Leo - mag. +2.1) to Vindemiatrix (ε Vir - mag. +2.8). M58 is located on the southern side of this line, just over halfway along. Positioned one degree east of M58 is M59 and M60 with M89 located one degree to the northwest of M58.
The galaxy was one of Charles Messier original discoveries. He found it on April 15, 1779; the same night he located elliptical galaxies M59 and M60, which were discovered a few days earlier by Johann Gottfried Koehler. Along with M91, M95 and M109, it's one of four barred spiral galaxies in the Messier catalogue.
M58 is a fine galaxy for backyard observers. It's visible in larger binoculars (e.g. 20x80s) as a small faint near circular haze of light. A 100mm (4-inch) scope will easily show the bright nucleus of M58. With a 200mm (8-inch) telescope under dark skies and good seeing conditions it's possible to see hints of the central bar structure. Larger scopes show more subtle details but not a great deal more. The galaxy covers 6.0 x 4.8 arc minutes of apparent sky. Despite not being terrifically detailed, M58 is large and bright enough to be impressive through most backyard scopes. Some 30 arc minutes southwest of M58 is a curious pair of interacting galaxies NGC 4567 and NGC 4568, popularly called the Siamese Twins.
M58 has an active galactic nucleus, which contains a supermassive black hole and some starburst activity. Two supernovae have been observed in M58; a type II supernova at mag. +13.5 in 1998 and a mag. +12.2 type I supernova a year later.
The galaxy is one of the earliest recognized spiral galaxies and was listed by Lord Rosse as one of 14 "spiral nebulae" discovered to 1850.
M58 Data Table
|Object Type||Barred spiral galaxy|
|RA (J2000)||12h 37m 44s|
|DEC (J2000)||11d 49m 05s|
|Apparent Size (arc mins)||6.0 x 4.8|
|Number of Stars||400 Billion|
|Notable Feature||M58 is one of the brightest galaxies in the Virgo cluster|