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Contains:  NGC 3193, NGC 3189, NGC 3190, NGC 3187, NGC 3185
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HCG 44, LRGB, 1 Feb & 15-16 Mar 2019, 





    
        

            David Dearden
HCG 44, LRGB, 1 Feb & 15-16 Mar 2019

HCG 44, LRGB, 1 Feb & 15-16 Mar 2019

Technical card

Resolution: 1878x1387

Dates:Feb. 1, 2019March 15, 2019March 16, 2019

Frames:
ZWO Blue 31 mm: 7x120" (gain: 139.00) -20C bin 1x1
ZWO Green 31 mm: 18x120" (gain: 139.00) -20C bin 1x1
ZWO Luminance 31 mm: 30x300" (gain: 139.00) -20C bin 1x1
ZWO Red 31 mm: 8x120" (gain: 139.00) -20C bin 1x1

Integration: 3.6 hours

Avg. Moon age: 14.86 days

Avg. Moon phase: 48.08%

Bortle Dark-Sky Scale: 5.00

Astrometry.net job: 2588562

RA center: 154.463 degrees

DEC center: 21.920 degrees

Pixel scale: 1.719 arcsec/pixel

Orientation: 180.989 degrees

Field radius: 0.557 degrees

Locations: Mapleton Lateral Observatory, Mapleton, Utah, United States

Data source: Backyard

Description

Even though I have long been intrigued by the variety of galactic shapes in this cluster, it seems like this target has always given me fits such that I just can’t get a good result. I took the luminance data for this image weeks ago, but this has been a cloudier-than-usual season so I didn’t get color to go with it until recently. And even then I had issues, as apparently my guider locked on a hot pixel after the automated meridian flip so I threw away nearly all my R and B subs. As a result, it was a huge struggle to bring out any color in this image. There was also angular misalignment between the luminance and color subs, so I had to crop far more than I wanted (I’m not a fan of cropping my data any more than I have to, even though it would often frame things better if I cropped; I like to show everything the camera caught when I can). And the final image is still a lot noisier than I like. Anyway, it’s better than my best previous (which says something about my best previous) so here it is.

Date: 1 Feb, 15-16 Mar 2019
Subject: HCG 44
Scope: AT8IN+High Point Scientific Coma Corrector
Filters: ZWO 31 mm diameter unmounted 7 nm L, R, G, B
Mount: EQ-6 (EQMOD 2.000j)+PEC
Guiding: Orion Thin Off-axis Guider + DSI IIc +PHD 2.6.5dev6 (Win 10 ASCOM)
Camera: ASI1600MM-Cool, -20 °C, Gain 139 Offset 21
Acquisition: Sequence Generator Pro 3.0.3.170
Exposure: 30x300 L, 8x120 R, 18x120 G, 7x120 B
Stacking: Deep Sky Stacker 4.1.1 (64-bit) dark+flat (no bias), κ-σ stacking with κ = 1.5.
Processing: StarTools 1.4.341: Combined L, R, G, & B in StarTools (had to convert R, G, & B to tiff first for some reason (they wouldn’t load otherwise). Cropped, wiped, developed, HDR optimized, and used the color module. Deconvoluted, untrack denoised. The did the same treatment to the L by itself and to the RGB. I ended up layering the processed RGB on top of the LRGB as a color layer in Photoshop. Attempted some more denoising and used increase star color.

Comments

Author

dvdearden
David Dearden
License: None (All rights reserved)
1652
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HCG 44, LRGB, 1 Feb & 15-16 Mar 2019, 





    
        

            David Dearden