M100 in Coma Berenices
M100 / Messier 100 (also known as NGC 4321) is a grand design intermediate spiral galaxy located within the southern part of constellation Coma Berenices. It is one of the brightest and largest galaxies in the Virgo Cluster, located approximately 55 million light-years distant from Earth and has a diameter of 107,000 light years, roughly 60% the size of the Milky Way. It was discovered by Pierre Méchain on March 15, 1781 and was subsequently entered in Messier’s catalogue of nebulae and star clusters after Charles Messier made observations of his own on April 13, 1781. The galaxy was one of the first spiral galaxies to be discovered, and was listed as one of fourteen spiral nebulae by Lord William Parsons of Rosse in 1850. NGC 4322 (right) and NGC 4328 (top) are satellite galaxies of M100; the former is connected with it by a bridge of luminous matter.
North is to the right in this image.
[description from Wikipedia]