Hemisphere:  Northern  ·  Contains:  5 Ser  ·  IC4537  ·  M 5  ·  M5  ·  NGC 5904  ·  The star 5Ser
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M5, RGB, 7 May 2020, 


            David Dearden
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M5, RGB, 7 May 2020

Imaging telescopes or lenses: Astro-Tech AT8IN

Imaging cameras: ZWO ASI1600MM-Cool

Mounts: Skywatcher NEQ-6 Pro Synscan

Guiding telescopes or lenses: Astro-Tech AT8IN

Guiding cameras: ZWO AS120MM-Mini

Focal reducers: High Point Scientific Coma Corrector Photo & Visual For Netwonian Telescopes 2"

Software: DeepSkyStacker  ·  Noel Carboni's Astro Tools for PhotoShop  ·  StarTools  ·  AstroPlanner  ·  PHD2 Guiding  ·  Sequence Generator Pro  ·  EQASCOM  ·  photoshop

Filters: ZWO Red 31 mm  ·  ZWO Green 31 mm  ·  ZWO Blue 31 mm

Accessory: Orion Thin Off Axis Guider (TOAG)  ·  Robert Brown's Arduino ASCOM Focuser Pro DIY  ·  ZWO EFW filter wheel

Dates:May 7, 2020May 8, 2020

ZWO Blue 31 mm: 30x120" (gain: 139.00) -20C bin 1x1
ZWO Green 31 mm: 30x120" (gain: 139.00) -20C bin 1x1
ZWO Red 31 mm: 30x120" (gain: 139.00) -20C bin 1x1

Integration: 3.0 hours

Avg. Moon age: 15.38 days

Avg. Moon phase: 99.21%

Bortle Dark-Sky Scale: 5.00

Astrometry.net job: 3496298

RA center: 15h 18' 40"

DEC center: +2° 1' 25"

Pixel scale: 1.720 arcsec/pixel

Orientation: 1.108 degrees

Field radius: 0.598 degrees

Resolution: 1898x1633

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

Data source: Backyard


24,500 LY

After trying some galaxies using LRGB under nearly full Moon conditions and failing miserably, I decided to try something I was pretty sure would work, globular clusters. Hence, M5. After taking a luminance sub I realized the sky background was still way too bright, so I used R, G, & B filters without any L. I felt like I cheated in several ways on this image. I used 2’ subs rather than the usual 3’ I have been using for most LRGB imaging lately, and cheating came in the form of using 3’ darks rather than taking the time to get proper 2’ ones. I can see I need to shoot some new flats as well because I’ve got some new dust donuts the flats are not removing. Thanks to the nearby full Moon, there were strong gradients in the stacked image I had to take out in software. I understand this cluster is believed to be very old, just a couple of billion years younger than the universe itself. That’s a sobering thought!

Date: 7 May 2020
Subject: M5
Scope: AT8IN+High Point Scientific Coma Corrector
Filters: ZWO 31 mm diameter unmounted R, G, B
Mount: EQ-6 (EQMOD 2.000j)+PEC
Guiding: Orion Thin Off-axis Guider + ASI120MM-mini +PHD 2.6.7 (Win 10 ASCOM)
Camera: ASI1600MM-Cool, -20 °C, Gain 139 Offset 21
Acquisition: Sequence Generator Pro
Exposure: 30x180 R, 30x180 G, 30x180 B
Stacking: Deep Sky Stacker 4.2.3 (64-bit) dark+flat+bias, κ-σ stacking with κ = 1.5
Processing: StarTools 1.6.392 beta: Combined R, G, & B in StarTools. Software binned 2x2, cropped, gradient wiped (95%), developed, HDR (reveal core), slight deconvolution, color, untrack denoised (grain equalization). A little bit of levels, some clone stamp work to remove dust donuts. AstroFrame.



David Dearden
License: None (All rights reserved)

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M5, RGB, 7 May 2020, 


            David Dearden