NGC 4490

NGC 4490, also known as the Cocoon Galaxy, is a barred spiral galaxy in the constellation Canes Venatici. William Herschel discovered it in 1788. It is known to be of the closest interacting/merging galactic system. The galaxy lies at a distance of 25 million light years from Earth making it located in the local universe. It interacts with its smaller companion NGC 4485 and as a result is a starburst galaxy. NGC 4490 and NGC 4485 are collectively known in the Atlas of Peculiar Galaxies as Arp 269. The two galaxies has already made their closest approach and are rushing away from each other. It's been discovered that NGC 4490 has a double nucleus.

NGC 4490 is located 3/4° northwest of beta Canum Venaticorum and with apparent visual magnitude 9.8, can be observed with 15x100 binoculars. It is a member of the Herschel 400 Catalogue. It belongs to the Canes II Group.

Stellar stream
A stellar stream 25,000 light years long connects the two interacting galaxies. The stellar stream is made of bright knots and large gas rich pockets. Young blue hot massive stars are formed in this region.

Supernova
Two supernovae have been observed in NGC 4490: SN 1982F, a supernova of a unknown type and has a magnitude of16, and SN 2008ax, a type II supernova with a magnitude of 13.