Hemisphere:  Northern  ·  Constellation: Gemini (Gem)  ·  Contains:  M 35  ·  NGC 2158  ·  NGC 2168
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M35 and NGC 2158 - a treasure trove, 



    
        

            Tom Gray
M35 and NGC 2158 - a treasure trove
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M35 and NGC 2158 - a treasure trove

Getting plate-solving status, please wait...
M35 and NGC 2158 - a treasure trove, 



    
        

            Tom Gray
M35 and NGC 2158 - a treasure trove
Powered byPixInsight

M35 and NGC 2158 - a treasure trove

Technical card

Imaging telescopes or lenses: William Optics Zenithstar II 80 ED

Imaging cameras: Meade DSI 3 Pro

Mounts: Meade LX6 premier with 'smartdrive'

Guiding telescopes or lenses: Meade 8x50mm Finder/Guider

Guiding cameras: Orion Starshoot autoguider

Software: SiliconFields / Ivo Jager StarTools v1.6  ·  Stark Labs Nebulosity v3  ·  PHD2 Guiding V 2.6  ·  Meade Envisage V4.10

Filters: Meade RGB-IR Cut 1.25"  ·  Meade LRGB 1.25"

Accessory: Homemade Dew Controller  ·  Homemade ST4 autoguider


Dates:Feb. 10, 2021

Frames:
Meade Blue Filter for CCD: 128x30" (1h 4') bin 2x2
Meade Green Filter for CCD: 32x30" (16') bin 2x2
Meade RGB-IR Cut 1.25": 39x60" (39') bin 1x1
Meade Red Filter for CCD: 30x30" (15') bin 2x2

Integration: 2h 14'

Darks: ~39

Flats: ~20

Avg. Moon age: 28.23 days

Avg. Moon phase: 1.89%

Bortle Dark-Sky Scale: 4.00

Mean FWHM: 5.00

Temperature: -6.00


Basic astrometry details

Astrometry.net job: 4507325

RA center: 6h 8' 16"

DEC center: +24° 16' 44"

Pixel scale: 2.418 arcsec/pixel

Orientation: 359.636 degrees

Field radius: 0.566 degrees


Resolution: 1347x1011

Locations: Home 'observatory' (Bortle 5), Derbyshire, United Kingdom

Data source: Backyard

Description

A promised night of clear, but freezing skies, offered much, but delivered relatively little - clear spells, poor transparency, and definitely cold! After weeks of cloud, I was determined to make the best of it...

M35 is jewel box of the winter sky, ~3000 LY away, comprising bright blue-white main sequence stars and a few older orange-red stars, spanning ~30LY. NGC 2158 by contrast looks tiny, but this 'puddle of gold dust' is of similar size, only 6x further away, and believed to be 2 billion years old. A treasure trove on a hard winters night.

A couple of developments made this a surprisingly enjoyable evening - firstly, I used the excellent phone App, Polarscope Align Pro [https://astro.ecuadors.net/polar-scope-align/] to find this object on my 'push to' LX6 mount, which put me in the right place each time. I am planning to fit some encoders to use my trusty ArgoNavis [http://www.wildcard-innovations.com.au/]. Secondly, I realise that I have not been preparing my data properly in Nebulosity for processing in Startools - specifically aligning all my images first, before stacking using sigma clip.

Captured LRGB in Envisage, reduction in Nebulosity and then straightforward Startools processing (especially the wipe function, which I have found very hard to use in the past). Hopefully this will ensure I don't end up clipping my data in an attempt to minimise gradients and other issues with sub-standard images.

Comments

Revisions

  • M35 and NGC 2158 - a treasure trove, 



    
        

            Tom Gray
    Original
  • M35 and NGC 2158 - a treasure trove, 



    
        

            Tom Gray
    B
  • Final
    M35 and NGC 2158 - a treasure trove, 



    
        

            Tom Gray
    C

B

Description: A slightly sharpened version, in RGB colour, with some reduction in magenta/violet halos using 'fringe killer' filter in Startools - I expect these are produced in part by my semi-APO doublet.

Uploaded: ...

C

Description: Reprocessed using ASTAP to calibrate, align and stack best 60% frames. Processed in Startools. Annoying (anti-blooming?) artifacts from camera and some colour fringing from my semi-APO doublet. A sharper image overall, but colour was difficult to manage.

Uploaded: ...

Sky plot

Sky plot

Histogram

M35 and NGC 2158 - a treasure trove, 



    
        

            Tom Gray