Whirlpool Galaxy

M51 as seen by the Hubble Space Telescope

Observation Data
Epoch: J2000
Constellation: Canes Venatici
Right Ascension: 13h 29m 52.7s
Declination: +47° 11′ 43″
Apparent Dimensions (V): 11′.2 × 6′.9
Apparent Magnitude (V): 8.4
Absolute Magnitude (V):
Type: SA(s)bc pec
Helio Radial Velocity: 600 km/s
Redshift: 0.002000
Galactocentric Velocity: 687 ± 4 km/s
Distance: 23 ± 4 Mly (7.1 ± 1.2 Mpc)
Other Designations
Question Mark Galaxy, Rosse's Galaxy, M51a, NGC 5194, UGC 8493, PGC 47404, VV 001a, VV 403, Arp 85, GC 3572

M51 is a luminous spiral galaxy that is experiencing mass star birth. It is interacting with its neighboring galaxy NGC 5195, a smaller Lenticular galaxy that is considered part of the whirlpool galaxy.

The nucleus of the galaxy has an x-shaped structure. The main body has a very active core, similar in size to the Milky Way, and the dormant member of a small group of galaxies called the M51 Group that includes M63, the Sunflower Galaxy.