Celestial hemisphere:  Northern  ·  Constellation: Cassiopeia (Cas)  ·  Contains:  27 gam Cas  ·  IC 59  ·  IC 63  ·  Sh2-185  ·  The star Navi (γCas)  ·  gamma Cas nebula
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IC 63, Gamma Cassiopeiae Nebula, The Ghost of Cassiopeia, HαRGB (Starizona Method 2), 6 Sep 2018, David Dearden
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IC 63, Gamma Cassiopeiae Nebula, The Ghost of Cassiopeia, HαRGB (Starizona Method 2), 6 Sep 2018

Getting plate-solving status, please wait...
IC 63, Gamma Cassiopeiae Nebula, The Ghost of Cassiopeia, HαRGB (Starizona Method 2), 6 Sep 2018, David Dearden
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IC 63, Gamma Cassiopeiae Nebula, The Ghost of Cassiopeia, HαRGB (Starizona Method 2), 6 Sep 2018

Equipment

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Description

I’ve had several nice nights in a row. I like this target and it was well-placed for HαRGB imaging. (I actually forgot I had done an HO version last year with the same gear, or I might have passed on it for something else this year.) I considered trying LRGB, but decided Hα would probably show more. I’ve been having some issues with my calibration, so these were done with no bias correction. (I think I actually need a new set of darks, after stacking with various components removed, but removing the bias also seemed to work). I vacillated back and forth about whether I liked the results from Starizona Method 1 or Method 2 better, and finally tried to get the best of both worlds by separating out the stars from Method 1 using Annie’s Astro Actions (the Method 1 stars definitely looked better) and layering them onto the Method 2 image via screen combine (the Method 2 nebula looked better). I think this worked OK, although I also still really like the pure Method 1 image.

Date: 6-7 Sep 2018

Subject: IC 63 and vicinity, γ Cassiopeiae Nebula or The Ghost of Cassiopeia

Scope: AT8IN+High Point Scientific Coma Corrector

Filters: ZWO 31 mm diameter unmounted 7 nm Hα, R, G, B

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 3.0.2.94

Exposure: 34x300 Hα, 20x180 R, G, & B

Stacking: Deep Sky Stacker 4.1.1 (64-bit) dark+flat (no bias), κ-σ stacking with κ = 1.5.

Processing: StarTools 1.4.332: Combined R, G, & B in StarTools. Cropped but no wipe was needed, developed, HDR optimized, and applied default color module settings. Denoised without any deconvolution. Cropped Hα data the same way, developed, HDR optimized, and deconvoluted before using untrack denoising. In Photoshop, used Starizona Method 2 to create HαR layer which I used to replace R in the RGB, then used Hα for luminance. Applied some curves and levels to bring up the nebula a bit more, then added the Method 1 stars on top via screen combine. Used a couple of rounds of “increase star color”, followed by a couple of rounds of “make stars smaller”. Did a little layer-masked levels to decrease the glare around γ Cas but this was a bit half-hearted, then AstroFrame.

Comments

Revisions

  • IC 63, Gamma Cassiopeiae Nebula, The Ghost of Cassiopeia, HαRGB (Starizona Method 2), 6 Sep 2018, David Dearden
    Original
  • Final
    IC 63, Gamma Cassiopeiae Nebula, The Ghost of Cassiopeia, HαRGB (Starizona Method 2), 6 Sep 2018, David Dearden
    B

B

Description: Method 2 version

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IC 63, Gamma Cassiopeiae Nebula, The Ghost of Cassiopeia, HαRGB (Starizona Method 2), 6 Sep 2018, David Dearden