Messier 58, NGC 4579

Messier 58 (NGC 4579) is a barred spiral galaxy in the constellation Virgo, one of the four barred spiral galaxies in Messier's catalog. It was discovered by Charles Messier in 1779, and listed by Lord Rosse as one of the first fourteen "spiral nebulae" known before 1850.

At magnitude 9.7, this galaxy is one of the brightest in the Virgo cluster. In smaller telescopes, it looks similar to the Virgo ellipticals, showing only its bright nucleus. Under good conditions, 4-inch or larger scopes show a 5.5' x 4.5' disk, of uneven brightness, with condensations that coincide with brighter areas of the spiral arms.

A suggestion of M 58's bar may be noticed with telescopes starting from 8-inch, as an extension of the central nucleus in an east-west direction. Because its bar is not very prominent, M 58 is often classified as intermediate between "normal" and barred spiral, or SABc.

Two supernovae have been observed in M 58: the type II supernova 1988A, found at mag 13.5 in January, 1988; and the type I supernova 1989M, discovered at mag 12.2 in June, 1989.

NGC 4579 is at a distance of approximately 68 million light-years, with a diameter of about 50,000 light-years. It contains some 100 billion stars, and is moving away from us at a rate of about 1500 km/sec. From its discovery in 1779, until the release of the New General Catalog in the 1880s, it was arguably (though unknown at that time) the farthest known astronomical object.