Interacting galaxies in the context of Satellite galaxy

A starburst galaxy is one undergoing an exceptionally high rate of star formation, as compared to the long-term average rate of star formation in the galaxy, or the star formation rate observed in most other galaxies.

For example, the star formation rate of the Milky Way galaxy is approximately 3 M_☉/yr, while starburst galaxies can experience star formation rates of 100 M_☉/yr or more. In a starburst galaxy, the rate of star formation is so large that the galaxy consumes all of its gas reservoir, from which the stars are forming, on a timescale much shorter than the age of the galaxy. As such, the starburst nature of a galaxy is a phase, and one that typically occupies a brief period of a galaxy's evolution. The majority of starburst galaxies are in the midst of a merger or close encounter with another galaxy. Starburst galaxies include M82, NGC 4038/NGC 4039 (the Antennae Galaxies), and IC 10.

Seyfert's Sextet is a group of galaxies about 190 million light-years away in the constellation Serpens. The group appears to contain six members, but one of the galaxies, NGC 6027d, is a background object (700 million light years behind the group) and another "galaxy," NGC 6027e, is actually a part of the tail from galaxy NGC 6027. The gravitational interaction among these galaxies should continue for hundreds of millions of years. Ultimately, the galaxies will merge to form a single giant elliptical galaxy.

The NGC 4038 Group is a group of galaxies in the constellations Corvus and Crater. The group may contain between 13 and 27 galaxies. The group's best known galaxies are the Antennae Galaxies (NGC 4038/NGC4039), a well-known interacting pair of galaxies.