APOD 3.6

http://apod.nasa.gov/apod/ap110226.html

This photograph shows ARP 227 (name from Halton Arp Catalogue of Galaxies, published by Caltech) Shell galaxies near the edge of Pisces, the Fish. It lies around 100 million light-years away from Earth. ARP 227 is made up of two prominent galaxies, NGC 474 and NGC 470. The 'shells' in 474 formed as density waves in a dynamically cold component (thick disk) during a flyby interaction with another galaxy. The field of view is 25 arc minutes.