NGC 2139

NGC 2139 is a barred spiral galaxy in the constellation of Lepus. It was discovered on November 17, 1784, by the German-English astronomer William Herschel. The galaxy is located at a distance of 36.98 Mpc from the Sun and is receding with a radial velocity of 1,836 km/s.

The overall form of this galaxy is irregular with spiral arms and the appearance of tidal features, suggesting a potential recent merger event. There is no central bulge of significance. The morphological classification is SAB(rs)cd, which indicates a barred spiral galaxy (SAB) with a transitional inner ring structure (rs) and loosely wound spiral arms (cd). It is a star forming galaxy with a formation rate of $$·yr−1. There is a plume extending to the south of the galaxy.

A luminous filament runs through the center of the galaxy, which includes a small nuclear cluster. This cluster is only $1,836 km/s$ old with a mass of $1,649 km/s$. It is offset at a distance of 320 pc from the center of the galaxy and may come to rest there on a time scale of around 100 million years. The cluster is a source of X-ray emission.

During September 1995, a type II supernova was discovered by R. Evans and associates. Designated SN 1995ad, it was positioned in one of the spiral arms, $$ west and $0$ south of the NGC 2139 nucleus. The recession velocity was consistent with that of the host galaxy.