NGC 4631 (Whale) & 4656 (Crowbar) Galaxies, 27 Apr 2015 (David Dearden)

NGC 4631 (Whale) & 4656 (Crowbar) Galaxies, 27 Apr 2015

To say sky conditions were marginal is being generous. Lots of Moon and lots of clouds almost made me give up on this image, but eventually the clouds moved off enough to get some data so I took what I could get. Synched from Cor Caroli with the PicGoto and as usual was right on target. Clouds messed up my guiding right after finding, but once things cleared I repeated the goto from Cartes du Ciel (without resynching) and surprisingly this put me right back dead center, so the software is doing a good job of tracking my actual sky position. Wanted to use 600 s subs, but the sky was too bright for that. Still not using my chiller, CCD temperatures from about 13 °C down to about 9 °C. After all was said and done, the image turned out better than expected and certainly better than my best previous effort on this target.

Date: 27 Apr 2015

Subject: NGC 4631 (Whale) and NGC 4656 (Crowbar) Galaxies

Scope: Astrotech AT8IN+Antares 0.5x focal reducer

Filter: Baader Fringe Killer

Mount: CG-5 (Synta motors, PicGoto Simplificado)

Guiding: 9x50 Finder/Guider + DSI Ic + PHD 2.5pre3 (Win 7 ASCOM)

Camera: DSI IIc no cooling (about 13 °C)

Acquisition: Nebulosity 3.3.3, no dither

Exposure: 40x300 s

Stacking: Neb 3.3.3, bad pixel map, bias included, 33 flats, normalize, deBayer & square. Stack the preprocessed, pre-aligned images in DSS, 95% filter, 2x drizzle, mean κ (1.5) σ rejection.

Processing: StarTools 1.3.5.289 Crop; Wipe: 88%; Develop: 64.25%; HDR:Reveal core; Color:Cap green to yellow, Scientific 402%; Deconvolute 5.0 pix; Life:Moderate; Track 6.6 pix, smoothness 85%; Magic:Shrink 1 pix. Photoshop CC 2014 + Carboni Astronomy Tools Deep space nr; Increase star color; Astroframe.

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Status	Advanced success
Started	...
Astrometry.net job	622989
PixInsight job	LNH8ZWKJHT9DYBRTNWRH8ZCD916XDU8B
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	12h42m56s.47
RA (top/left)	12h44m52s.63
RA (top/right)	12h43m02s.75
RA (bottom/right)	12h41m00s.10
RA (bottom/left)	12h42m49s.97

Dec (center)	+32°21′55″.8
Dec (top/left)	+32°12′57″.9
Dec (top/right)	+32°48′03″.7
Dec (bottom/right)	+32°30′47″.4
Dec (bottom/left)	+31°55′48″.5

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