This image shows the central part of the Abell 1185 cluster of galaxies in Ursa Major.? The cluster is roughly 450M light-years away and contains 80+ confirmed members.? One striking component of the cluster is the peculiar collection of distorted galaxies below center.? These were catalogued in Arp's atlas of peculiar galaxies and given the appellation of "the guitar". The object is comprised of elliptical, spiral, and tidal dwarf galaxies that are undergoing dramatic gravitational interactions. The "neck" of the guitar represents stellar material that has been extracted from the blue dwarf galaxy at the left and the bright blue knot to the right of the elliptical galaxy is thought to be the end of that tidal stream.? The largest elliptical galaxy in the upper left is NGC 3550 which exhibits a rare triple nucleus.? Those nuclei have very different velocities and are therefore presumed to be the result of recent mergers of at least 3 galaxies.? The image was captured during 8 nights in May and June 2023. Image acquisition was done with a 12.5" PlaneWave scope and a QSI-640ws camera at f/8 for a final LRGB integration of 16 hours.



Thanks for looking,
Bruce W.