The interacting galaxy triplet NGC 5761 in Libra, shown from a 2-minute red-light exposure with an RCA CCD in the EFOSC system at the 3.6-meter telescope of the European Southern Observatory on Cerro La Silla, Chile. North is at the top and east to the left, for direct comparison with a chart or eyepiece view. The image uses a logarithmic intensity transformation to preserve information across a wide dynamic range. The field is 2.9 arcminutes square.
The members of this system contrast the ways that different kinds of galaxies respond to gravitational perturbation. The small disk galaxy to the southwest (lower rigt) shows extravagant tails, the result of tides tugging on a thin, rotating disk. The big elliptical shows only the mildest asymmetry, not only because it's bigger but because elliptical galaxies are dynamically "hot". That is, their stars are going in all directions rather than flying in formation as in a disk, so that disturbances are smeared out rather than all going into a single thin tail or bridge.
Last changes: August 1997