NGC 3718, NGC 3729 and Hickson 56 (UMa)

NGC 3718, NGC 3729 and Hickson 56 (UMa)

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Date/Site:	7. and 19. March 2021. Remote observatory on the AAR club's site in Presberg
Exposure/ Filter:	R: 22 x 300 seconds, G: 18 x 300 seconds, B: 16 x 300 seconds, L: 26 x 300 seconds (-20°C)
Camera:	Moravian G3-16200 with Astronomik Type II-filters
Optics/ Instrument:	250mm f/4,7 Newton with VIP-3010 Paracorr on 10Micron GM1000 HPS
	Guiding: Lodestar attached to a 61mm-finder, focusing: Microtouch and FocusMax, data acquired remotely using CCD-Commander and MaximDL 6, processing: MaximDL 6 and PixInsight 1.8

This group of galaxies is one of my favourites. The tidally deformed galaxies in a distance of 56 million lightyears correspond dramatically with the interacting galaxies of the compact Hickson 56-group, which is 350 million lightyears distant.

Several years ago I imaged this group with totally different instruments:

NGC 3729/3718 (UMa)

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Date/Site:	April 1. and 20., 2009, AAR-observatory in Presberg
Exposure/ Filter:	Luminance 12 x 5 minutes (-20°C) with 13"-Newton, RGB 6 x 5 minutes (-25°C) with 6"-Newton
Camera:	SBIG ST10XME, motorized Atik-filterwheel with Astronomik-RGB-filters
Optics/ Instrument:	13"-Newton and 6"-Newton, Baader coma-corrector
	focusing with RoboFocus and MaximDL
	flatfielding, darks, deblooming, alignment and stacking: MaximDL levels and curves: Photoshop CS

Remarks: 5.5 mag-sky, dry, no wind, +3.5°C (1.4.) and +12°C (20.4.) with hight humidity.