Ralph Copeland first saw this fine galaxy-group in the constellation of Leo in 1874 with its 7-8 members of only 13.5-15.2mag brightness.
The most prominent galaxy is the Sab-typed and nearly edged-on NGC3753,sized 1,7′ × 0,5′ and approx.400mio.light-years away from us.
Apparently many members of this group are somewhat ineracting with each other.
Hickson also labeled this group as HCG57,and Arp listed this group as Arp320 in his ATLAS OF PECULIAR GALAXIES
position (epoch 2000):
Ra.: 11h 37m 53,9s
Decl.: +21° 58′ 53″
LRGB (460-140-140-140 min),a total of 14.7 hours
80cm f/7 AstroOptik Keller corrected cassegrain
FLI Proline 16803 Astrodon LRGB Gen-II filters
Prompt 7 CTIO/UNC Chile,remote controlled
image processing: Bernd Flach-Wilken
this squared 14.6´arc-min.wide sky-area in Leo shows the galaxies of Copeland´s Septet (Arp320) with its brightest
member NGC3753. North is up
For full resolution click HERE
here you can see a picture with higher magnification:
and finally here is a labeled one for helping to identify the members of this galaxy-group: