Wikipedia Notes: Stephan's Quintet in the constellation Pegasus is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered.[2] The group was discovered by Édouard Stephan in 1877 at Marseilles Observatory.[3] The group is the most studied of all the compact galaxy groups.[2] The brightest member of the visual grouping is NGC 7320 that is shown to have extensive H II regions, identified as red blobs, where active star formation is occurring.