Hemisphere:  Northern  ·  Constellation: Triangulum (Tri)  ·  Contains:  M 33  ·  NGC 595  ·  NGC 598  ·  NGC 604  ·  Triangulum Galaxy  ·  Triangulum Pinwheel
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M33 in dual band, 



    
        

            Tom Gray
M33 in dual band
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M33 in dual band

Getting plate-solving status, please wait...
M33 in dual band, 



    
        

            Tom Gray
M33 in dual band
Powered byPixInsight

M33 in dual band

Technical card

Imaging telescopes or lenses: William Optics Zenithstar II 80 ED

Imaging cameras: Meade DSI 3 Pro

Mounts: Meade Fork mount w/wedge Meade

Guiding telescopes or lenses: Meade 8x50mm Finder/Guider

Guiding cameras: Orion Starshoot autoguider

Focal reducers: Meade f3.3 focal reducer/field flattener Meade Focal reducer

Software: SiliconFields / Ivo Jager StarTools v1.6  ·  Stark Labs Nebulosity v3  ·  Penumbra (George Morimosato) v0.6  ·  Meade Envisage V4.05

Filters: Optolong L-eNhance 1.25"  ·  Meade LRGB 1.25"

Accessory: Homemade Dew Controller  ·  Homemade ST4 autoguider


Dates:Dec. 16, 2020Dec. 20, 2020

Frames:
Meade LRGB 1.25": 7x120" (14') bin 2x2
Meade LRGB 1.25": 26x120" (52')
Optolong L-eNhance 1.25": 38x300" (3h 10')

Integration: 4h 16'

Flats: ~25

Avg. Moon age: 4.01 days

Avg. Moon phase: 20.03%

Bortle Dark-Sky Scale: 4.00


Basic astrometry details

Astrometry.net job: 4103119

RA center: 1h 34' 21"

DEC center: +30° 42' 57"

Pixel scale: 4.808 arcsec/pixel

Orientation: 181.341 degrees

Field radius: 1.036 degrees


Resolution: 1234x940

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

Data source: Backyard

Description

After some success capturing this grand galaxy from a dark sky site in the summer, using my 8” SCT, I wanted to try a longer exposure with the wider field of view I can achieve with my refractor set up. This image taken in between the clouds over two nights, combines data at slightly different focal lengths, as I try and optimise the focal reduction on my Zenithstar. There is some vignetting at 4.8 pixels / arc second; hopefully ~4.5 pixels/“ should be optimum.

An hour of luminance data using an IR cut filter has been supplemented with a little red data, and (due to the waxing moon) over an hour of data from my narrow band filter. Mapping this to Green and Blue, has allowed me to produce a false colour HOO image in Startools.

Due to some haze, vignetting and aberration from my semi-APO the image is not pin sharp. I hope I can improve this by tweaking the focal length and capturing more data under better sky conditions. This is my longest integration so far, and I am enjoying capturing some wider fields and appreciate the less demanding tolerances of imaging with with my refractor.

Comments

Sky plot

Sky plot

Histogram

M33 in dual band, 



    
        

            Tom Gray