Messier Catalogue

A catalogue of star clusters, nebulae and galaxies originally published by Charles Messier in 1774. Although not particularly extensive (there are 110 Messier objects, as compared with 7,840 in the New General Catalogue) the Messier catalogue numbers (such as M1 for the Crab Nebula, or M42 for the Orion Nebula) are still in wide use.

The Virgo Cluster on the border of Virgo and Coma Berenices holds the sky's densest grouping of objects from the Messier Catalogue. This view of the heart of the cluster includes five Messier galaxies. The spiral galaxy to the top left is M90, and the four bright elliptical galaxies are, from left to right (east to west), M89, M87 (Virgo A), M86 and M84.