Sh2-132, Lion Nebula, HO Bicolor, 23 Jul & 31 Aug 2018 (David Dearden)

Sh2-132, Lion Nebula, HO Bicolor, 23 Jul & 31 Aug 2018

Between huge amounts of wildfire smoke and monsoon cloudiness (without much rain!) it has been a rough summer for imaging. It seemed every time the clouds went away the smoke appeared and vice versa. But finally I have some OIII to combine with Hα and allow a stab at this image. If the forecast holds, I might get SII and more RGB tonight to add. Sh2-132 is reasonably bright in Hα, but quite dim in OIII (and I’m skeptical about SII but better reserve judgment until I try it). In both cases I used 600-s subframes, twice as long as I usually do, because I wanted to pick up more of the nebula and the histogram didn’t show much saturation. I haven’t tried this object much so this is by far my best attempt at it so far.

Date: 23-24 Jul, 31 Aug-1 Sep 2018

Subject: Sh2-132, Lion Nebula

Scope: AT8IN+High Point Scientific Coma Corrector

Filters: ZWO 31 mm diameter unmounted Hα, OIII

Mount: EQ-6 (EQMOD 2.000j)+PEC

Guiding: Orion Thin Off-axis Guider + DSI IIc +PHD 2.6.5 (Win 10 ASCOM)

Camera: ASI1600MM-Cool, -20 °C, Gain 139 Offset 21

Acquisition: Sequence Generator Pro 3.0.2.91, 3.0.2.94

Exposure: 28x600 Hα, 24x600 OIII

Stacking: Deep Sky Stacker 4.1.1 (64-bit) dark+flat+bias, κ-σ stacking with κ = 1.5.

Processing: StarTools 1.4.332: Used similar process for Hα and OIII: binned 2x2, cropped, wiped, developed, HDR (optimize), deconvolution. Stopped tracking to smooth. Combined Hα with OIII in Photoshop using Annie’s Astro Actions, after shrinking the stars in the OIII to try and eliminate some of the blue halos that happen because I don’t seem to be able to focus OIII quite as well as Hα. Layered the Hα back on top as luminance. Boosted saturation. Used Carboni’s deep space and space noise reduction and 1 round of star shrinking. AstroFrame.

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Status	Advanced success
Started	...
Astrometry.net job	2228655
PixInsight job	ZKOD7L9KNIYT00V55YJB2Y9P8ZJ4KO6X
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	22h19m31s.12
RA (top/left)	22h23m08s.24
RA (top/right)	22h15m12s.44
RA (bottom/right)	22h15m59s.43
RA (bottom/left)	22h23m45s.10

Dec (center)	+56°03′21″.4
Dec (top/left)	+56°32′15″.1
Dec (top/right)	+56°24′35″.0
Dec (bottom/right)	+55°34′05″.4
Dec (bottom/left)	+55°41′34″.2

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