Messier 51, the Whirlpool Galaxy, is a classic face-on Sbc spiral galaxy in Canes Venatici.

M51 is located 30 million light-years away from us and is 60 thousand light-years in diameter. It shines at magnitude 8.4 and is 11 x 7 arcminutes in apparent size.

M51 was one of the original discoveries made by Charles Messier while comet hunting in 1773, and it was the first galaxy where spiral structure was observed, by Lord Rosse in 1845.

Companion galaxy NGC 5195 is seen to the left (north) of M51. It is interacting with M51. It was discovered by Pierre Méchain in 1781. NGC 5195 shines at magnitude 9.6 and is 5 arcminutes in diameter.

Supernova 2011dh, type II supernova, appeared in M51 in 2011. Hold your mouse cursor over the image to see its location.

The discovery was credited to Tom Reiland, Amedee Riou, Thomas Griga, and Stephane Lamotte Bailey. It occurred sometime between May 30 and May 31, 2011. At the time this image was taken four days later, the supernova was approximately at magnitude 14.5. It continued to brighten until June 19 when it peaked near apparent magnitude 12.1. The explosion is thought to have originated in a yellow supergiant star with 18 to 24 solar masses.

North is to the left in the above image.

M51 Catalogs: M51, NGC 5194 Common Name: Whirlpool, Lord Rosse's Question Mark Object Type: Galaxy Magnitude: 8.1v Size: 11.2' x 6.9' Constellation: Canes Venatici Image Field Centered At: RA: 13h 29m 54s Dec: +47° 12' 17"