NGC3753 Arp320 (Copeland´s Septet) Galaxy group in Leo

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″


image data:

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:


Last modified on Thursday, 08 April 2021 12:43

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