Object name: ARP240

Designation(s): ARP240, NGC5257, NGC5258,

Arp 240 consists of two spiral galaxies pulling material out of each other making a bridge between the two. Arp classified them under "Appearance of Fission". This is the same classification of "The Mice" and "Antennae" galaxies. Located some 300 million light-years from us I didn't get a lot of detail but you can see the bridge that connects the two galaxies. The two galaxies are NGC 5257 (right) and NGC 5258. About the same time I was taking this Hubble released a series of such colliding galaxies that included this pair. Here's a link to Hubble's image of this pair with a bit more about them.

NGC 5257 (right galaxy) is listed at NED as SAB(s)b pec;HII LIRG LIRG stands for Luminous Infra Red Galaxy. This usually means there's a lot of star formation going on behind dust that the stars heat creating the infrared light. NGC 5258 on the left is classified by NED as SA(s)b: pec;HII LINER. They were discovered by William Herschel on May 13, 1793 but didn't make either of the Herschel 400 observing programs.

Arp's image:

14" LX200R @ f/10, L=5x10' RGB=2x10'x3, STL-11000XM, Paramount ME