Sh2-188, Dolphin Nebula, OSC, 11 Nov 2015 (David Dearden)

Sh2-188, Dolphin Nebula, OSC, 11 Nov 2015

First time observation of this nebula, which does look to me like a dolphin leaping. I used the UHC-S filter because I wanted to reduce the effects of the Provo light dome, north of me. Synched from γ Cas, an easy PicGoto. I collimated carefully before this session to try to get a sharper image than my last one. That did seem to help, but I didn't find the collimation to be very far out. I also balanced a bit more carefully to try and get better guiding performance out of my mount. Balance is pretty critical with this mount/scope combination, and I got good performance up until my meridian flip, after which things got a bit worse. I had intended to do this image with Hα added, but in this case I don't think that is likely to improve it much; what I gain in contrast I will lose in resolution. This was one of the (at least recently) unusual cases where drizzle stacking did not improve the image.

Date: 11 Nov 2015

Subject: Sh2-188, Dolphin Nebula

Scope: AT8IN

Filter: Baader UHC-S

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

Guiding: Orion ST-80 + DSI Ic + PHD 2.5.0.7 (Win 7 ASCOM)

Camera: DSI IIc, no chiller CCD 2 °C

Acquisition: Nebulosity 4.0.3, no dither

Exposure: 52x600 s

Stacking: Neb 4, bad pixel map, bias included, 52 flats, OSC nebula filter, match histograms, deBayer & square, trans+rot align, 40-60%tile stack.

Processing: StarTools 1.4.305 Crop; Wipe 75%; Develop 86.18%; HDR optimize; Color: scientific, 200%; Deconvolute 3.5 pix; Track 4.5 pix, Smoothness 86%; Magic: shrink 2 pixels. CS6 Astronomy Tools increase star color; local contrast enhance; deep space noise reduction; make stars smaller; liquify/pucker; Astroframe.

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Status	Advanced success
Started	...
Astrometry.net job	845813
PixInsight job	NSQJ4VQSP0SNG1KMKR51PKSPUIK1XSMF
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	01h30m33s.30
RA (top/left)	01h28m49s.45
RA (top/right)	01h32m15s.87
RA (bottom/right)	01h32m18s.32
RA (bottom/left)	01h28m49s.32

Dec (center)	+58°25′13″.2
Dec (top/left)	+58°14′07″.5
Dec (top/right)	+58°13′43″.4
Dec (bottom/right)	+58°36′22″.0
Dec (bottom/left)	+58°37′04″.0

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