MS 0129.2-2237: Interacting Galaxies at Z = 0.11

The x-ray source MS 0129.2 - 2237 is positionally coincident with an interacting system of galaxies. We present the results of our spectroscopic and photometric investigation of the system, which show that a Seyfert 1.5, a Seyfert 2 nucleus or H II region or a starburst galaxy, a normal galaxy plus possibly another galaxy where star-forming activity is taking place are strongly interacting. The redshift of the system is z = 0.11. The maximum projected diameter of the envelope common to the four spectroscopi- cally distinct objects is ~98 kpc (H_0_ = 50 km s^-1^ Mpc^-1^ and q_0_ = 0.5). The isolated environment in which the system lies suggests that we are looking at the final stage of the life of a compact group of galaxies where members are merging into an elliptical galaxy.