These colliding galaxies are also known as NGC 4038 / 4039.  The bright area is sometimes called the "Ring-Tail Galaxy" even though it's two galaxies.  The lower galaxy (NGC 4039) is called the "Comma".  The Antenna name comes from the dim wings going up and to the left, and also down from the main bright area. The Antenna is in Corvus (the Crow) just below Virgo, and has a magnitude 10.9.  It is 5.3 by 3.1 arc-minutes in size.

This image is a composite of three 2x2 binned 10 minute exposures. Taken with the ST-8E and 12" LX200 at f/10.  Taken at the ARGO site in central Oregon on Apr 1, 2000.