Bob's AstroGallery

A.k.a. Whirlpool Galaxy
A.k.a. NGC 5194
A.k.a. Arp 85
Type: Spiral Galaxy
Distance from earth: Approx. 23.000.000 ly
Constellation: Canus Venatici (Hunting Dogs)
Telescope: Robtics 115mm triplet apo @ F/6.9
Camera: Atik 383L+ monochrome
Exposure: 8x 600s + 1x 600s dark
Filters: Hutech IDAS LPS-P2
Additional accessories: Robtics field flattener, Starlight Xpress USB filter wheel

The smaller, interacting galaxy is known as NGC 5195. Both galaxies are also referred to as M51a and M51b (the last one being the smaller galaxy).