Celestial hemisphere:  Northern  ·  Constellation: Hercules (Her)  ·  Contains:  IC 1178  ·  IC 1181  ·  NGC 6040  ·  NGC 6041  ·  NGC 6045  ·  NGC 6047  ·  NGC 6055  ·  NGC 6061
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Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019, David Dearden
Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019
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Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019

Getting plate-solving status, please wait...
Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019, David Dearden
Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019
Powered byPixInsight

Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019

Equipment

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Acquisition details

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Description

I was sure the AT8IN would do a better job on this cluster than the ST80 with a focal reducer did on my last attempt, and my Newtonian did come through. I had a bit more moonlight than I like for LRGB imaging, but bad weather is coming and this target was well placed. There are a huge number of faint fuzzies in this part of the sky, and this cluster is about 500 million light years away! This is currently the most distant target in my collection. The final result came out of StarTools’ color module with a lot of red, but I hesitate to arbitrarily mess very much with the color balance; I guess I need to learn some good techniques for properly adjusting it. I vacillated between the reddish and bluer versions, and I guess I’ll post both and seek opinions about which is better!

Date: 13, 14, 15 May 2019

Subject: Abell 2151, Hercules Galaxy Cluster

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 + ASI120MM-mini +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: 60x180 L, 20x180 R, 30x180 G, 20x180 B

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

Processing: StarTools 1.4.341: Cropped, wiped, developed, HDR optimized, deconvoluted, and untrack denoised the L data. Combined RGB in StarTools, cropped, wiped, developed, and used the color module on the RGB data, increasing the saturation. Untrack denoised. Combined L with RGB, performed deep space noise reduction, used several rounds of GradientXTerminator. One round of “less crunchy more fuzzy.” Used a couple of rounds of curves and levels to bring up faint objects, then used layer masked levels to deal with the background without losing them. AstroFrame.

Comments

Revisions

  • Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019, David Dearden
    Original
  • Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019, David Dearden
    B
  • Final
    Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019, David Dearden
    C

B

Description: This is the "bluer" version. I'm not sure which I like better, and would welcome suggestions/comments.

Uploaded: ...

C

Description: Here's an attempt to avoid clipping the black point. This one is much less processed than the other two versions, and maybe I like it best.

Uploaded: ...

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Abell 2151, Hercules Galaxy Cluster, LRGB, 13-15 May 2019, David Dearden