NGC 1579, The "Northern Trifid", Hα False Color Animation, 21 Nov 2015 (David Dearden)

NGC 1579, The "Northern Trifid", Hα False Color Animation, 21 Nov 2015

Switched back to Hα because there is so much moonlight now. Synched from Capella, and used the PicGoto + Astrotortilla to be sure I was on target. Once again, a lot went wrong with this image, primarily because I just can't seem to get my guiding to work well recently. The RA guiding was particularly off; maybe I need to retune my mount (or replace it!). 900 s subframes are pretty near the limit I can currently do with this mount at this imaging scale. This "Northern Trifid" is a lot dimmer than the southern one, so I struggled with the processing too. I may have deconvoluted too much in an attempt to bring out some detail in the nebula. This was another case where drizzle stacking didn’t seem to help, although I probably should go back and try 2x rather than the 3x I used initially. At some point when the nights are darker I'll need to come back to this and add some RGB.

Date: 21 Nov 2015

Subject: NGC 1579, The “Northern Trifid” Nebula

Scope: AT8IN

Filter: Baader UHC-S

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

Guiding: 9x50 mm finder/guider + DSI Ic + PHD 2.5.0.7 (Win 7 ASCOM)

Camera: DSI IIc, no chiller CCD -3 °C

Acquisition: Nebulosity 4.0.3, no dither

Exposure: 33x900 s

Stacking: Neb 4, bad pixel map, bias included, 33 flats, extract R channel, match histograms, square, trans+rot align, 40-60tile stack.

Processing: StarTools 1.4.305 Crop; Wipe 75%; Develop 85.05%; HDR optimize; Deconvolute 2.5 pix; Life: moderate; Track 4.5 pix, Smoothness 86%; Magic: shrink 1 pixel. CS6 Astronomy Tools resize 2x; make stars smaller; curves to bring up nebula a bit more; Astroframe; B&W—>Hα false color black space; assemble animated GIF.

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Status	Advanced success
Started	...
Astrometry.net job	860120
PixInsight job	JY07QWXH4816YGP78Y244XD1OJOKY21N
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	04h30m14s.50
RA (top/left)	04h31m21s.62
RA (top/right)	04h29m04s.62
RA (bottom/right)	04h29m06s.77
RA (bottom/left)	04h31m23s.22

Dec (center)	+35°15′26″.9
Dec (top/left)	+35°26′34″.8
Dec (top/right)	+35°26′05″.8
Dec (bottom/right)	+35°04′16″.8
Dec (bottom/left)	+35°04′45″.2

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