NGC3718 et al in Ursa Major


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Description: This unusual collection of galaxies has NGC3718, the larger one, and NGC3729, the smaller barred spiral to the right.  There is a tight grouping of 5 galaxies at the top from left to right: PGC35609, PGC35615, PGC35618, PGC35620 and PGC35631.  PGC35620 is severely distorted.  South is up.
Exposure Data: 5/13,14/2004.  LRGB: 50x3m, 12x3m, 12x3m, 12x3m. RGB binned 2x2.
-20C, 0.59 arc-sec./pixel.
Processing: Acquired via Sequencer II and CCDSoft, reduced, aligned and combined in Mira, L 20RL interations in AIP4WIN, RGB in Maxim, final combine, curves, levels and other processing in Photoshop.
Optical System: 14.5 Ritchey-Chretien RCOS Truss @ F/6.4, SBIG ST-10XME NABG/FLI CFW-2 CCD camera, Paramount ME. AstroDon filters with IR-filtered L. Unguided and dithered 4 arc-sec.
Comments: Luminance frame measured 2.5 arc-sec. before deconvolution and 1.6 arc-sec. after.