The list of the Hickson compact group galaxies is exotic and interesting. It consists of particularly tight groups with often strong gravitational interactions.
The small compact group of galaxies at the bottom is Hickson 56.
"The Box" is the name of this famous compact group.
This is Seyfert´s Sextet in Serpens. Originally discovered by Stephan at the Marseilles observatory in 1883. It has the designation NGC 6027. It is so compact, so all the galaxies got the same catalogue number. Note the tiny "round" galaxy in the group, which actually is a much more distant spiral galaxy.
This is Stephan's quintet. The upper right galaxy pair NGC 7318 a and b has also the designation Arp 319.
This is the NGC 7550 group, a quartet plus a fifth high redshift galaxy. Also designated Arp 99. "Spiral with elliptical companion on arm".
This is a septett of galaxies. Three galaxies are NGC 7578 a, b, c, also designated Arp 170. "Galaxies with diffuse counter-tail".
www.galaxies.se - Ivar Hamberg - Updated 2023, Oct 30.