Messier 100 is a spiral galaxy similar to our own Milky Way. It is located about 60 million light years away in constellation Virgo, and it is part of Vigo Cluster of Galaxies. M100 was discovered in March, 1781 by Pierre Mechain, and one month later has been introduced by Messier to its catalog. It is also one of Lord Rosse’s original 14 “spiral nebula”. M100 seems to employ a perfect spiral shape – the one without central bar structure. Charles Messier wrote in his notes:
“Nebula without star, of the same light as the preceding [M99], situated in the ear of Virgo. Seen by M. Mechain on March 15, 1781. The three nebulae, nos. 98, 99 & 100, are very difficult to recognize, because of the faintness of their light: one can observe them only in good weather, and near their passage of the Meridian.”
M100 galaxy has two distinct arms of young, hot and massive stars and that can be seen at photographies. There are two satellite galaxies NGC4323 and NGC4328 – this first one is connected to M100 by a bridge of luminous matter. M100 is also considered as starburst galaxy. The strongest star formation activity is concentrated in its center.
I made image below at my backyard roll-off shed. Telescope: Meade ACF 10″, camera: QHY163M, mount: EQ6. Guided with 80/400 refractor and ASI290MM camera. Conditions: suburban sky, medium transparency and seeing. It is LRGB composition built up with 2 minutes subframes – about 3 hours of total exposure time.