Getting plate-solving status, please wait...
M101 - in your face, 


            Tom Gray

M101 - in your face

Getting plate-solving status, please wait...
M101 - in your face, 


            Tom Gray

M101 - in your face

Technical card

Imaging telescopes or lenses: Meade 2080 SCT 8" LX5

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 f6.3 focal reducer/field flattener Meade 0.63x Reducer

Software: Han Klein ASTAP v0.915  ·  SiliconFields / Ivo Jager Startools v1.7  ·  PHD2 Guiding V 2.6  ·  Meade Envisage V4.10

Filters: Meade RGB-IR Cut 1.25"

Accessory: Bahtinov Mask  ·  Homemade ST4 autoguider  ·  Finder guider 8x50 Finder Scope

Dates:April 6, 2021

Frames: 25x120" (50')

Integration: 50'

Avg. Moon age: 24.25 days

Avg. Moon phase: 28.37%

Basic astrometry details job: 4384296

Resolution: 1348x1010

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

Data source: Backyard


My final attempt on a night of poor seeing, and atmospheric turbulence. M101 is enormous, 70% larger than our Milky Way, and lies around 26m LY away - as a result it has a low surface brightness. It has a high proportion of HII regions and despite the poor seeing, and smearing, these are clearly visible as brighter patches round the spiral arms (a number of these have their own reference in the NGC). Sadly the young blue star forming regions are not clear, and given the conditions, it was not worth adding colour data. I’ll try this agin, on a better night, at a smaller scale, so it is not quite so ‘in your face’ (even the plate solver had difficulty with this one) - it seems we’ve all grown used to social distancing!

ASTAP forced me to throw away at least a 1/3 of my data, so this comprises just under an hour of luminance frames. I managed to drag a little detail our of the atmospheric chaos with Startools.