Deep optical imaging of a compact group of galaxies, Seyfert's Sextet

To investigate the dynamical status of Seyfert's Sextet (SS), we have obtai ned a deep optical (VR + I) image of this group. Our image shows that a fai nt envelope, down to a surface brightness mu (option)(AB) similar or equal to 27 mag arcsec(-2), surrounds the member galaxies. This envelope is irreg ular in shape. It is likely that this shape is attributed either to recent- past or to ongoing galaxy interactions in SS. If the member galaxies have e xperienced a number of mutual interactions over a long timescale, the shape of the envelope should be rounder. Therefore, the irregularly shaped morph ology suggests that SS is in an early phase of dynamical interaction among the member galaxies. It is interesting to note that the soft X-ray image ob tained with ROSAT (Pildis, Bregman, & Evrard) is significantly similar in m orphology. We discuss the possible future evolution of SS briefly.