Hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  M 101  ·  M101  ·  NGC 5457  ·  NGC 5473  ·  NGC 5477  ·  NGC5447  ·  NGC5449  ·  NGC5450  ·  NGC5451  ·  NGC5453  ·  NGC5455  ·  NGC5461  ·  NGC5462  ·  NGC5471  ·  NGC5473  ·  NGC5477  ·  Pinwheel galaxy
M 101 LRGB, 



    
        

            Paul Muskee
Powered byPixInsight

M 101 LRGB

M 101 LRGB, 



    
        

            Paul Muskee
Powered byPixInsight

M 101 LRGB

Technical card

Imaging telescopes or lenses: William Optics FLT 132 Triplet APO

Imaging cameras: ZWO ASI 1600MM Cooled Pro

Mounts: Mesu Optics Mesu-Mount 200

Guiding telescopes or lenses: William Optics 50/200 GuideScope

Guiding cameras: Starlight Xpress Lodestar Autoguider X2

Focal reducers: Riccardi Reducer 0,75x

Software: Seqence Generator Pro  ·  Ripley PixInsight 1.8  ·  PHD2 Guiding Software  ·  Photoshop CC  ·  AstroPixelProcessor  ·  Bahtinov Grabber  ·  Sidereal Technology SiTechExe

Filters: Baader G Filter - 50mm  ·  Baader L Filter - 50mm  ·  Baader B Filter - 50mm  ·  Baader R Filter - 50mm

Accessory: Starlight Instruments Focus Boss II  ·  Starlight Xpress USB Maxi Filter Wheel 9x  ·  QHYCCD PoleMaster


Dates:April 13, 2019April 14, 2019April 19, 2019April 20, 2019

Frames:
Baader B Filter - 50mm: 169x90" (4h 13' 30") (gain: 1.00) -20C bin 1x1
Baader G Filter - 50mm: 85x90" (2h 7' 30") (gain: 1.00) -20C bin 1x1
Baader L Filter - 50mm: 420x60" (7h) (gain: 1.00) -20C bin 1x1
Baader R Filter - 50mm: 83x90" (2h 4' 30") (gain: 1.00) -20C bin 1x1

Integration: 15h 25' 30"

Avg. Moon age: 12.02 days

Avg. Moon phase: 81.45%

Bortle Dark-Sky Scale: 4.00


Astrometry.net job: 2793025

RA center: 14h 3' 14"

DEC center: +54° 21' 9"

Pixel scale: 1.142 arcsec/pixel

Orientation: 143.414 degrees

Field radius: 0.890 degrees


Resolution: 4476x3381

Locations: Lingemeer (backyard @ home), Lienden, Gelderland, Netherlands

Data source: Backyard

Description

M 101 preview taken during almost full moon.

A preview which has been quickly processed to see how good this data was. Most frames are taking during almost full moon. Nonetheless, it is looking good. However, I have some serious issues with some stars which started back in my previous image. Very annoying and gonna look for the cause of this.

Regarding imaging during full moon, I do not see why it is not possible... I only had some greens to remove but nothing special. Soon I will do a very extensive test: capture a object twice with exactly the same settings but one during (full) moon and one without moon at all. Since we do not have that many clear nights in NL I really want to investigate this...

Also have the Ha data for this object, but first I want to fix the star issue... So this will get updated anytime soon...

Comments

Revisions

  • M 101 LRGB, 



    
        

            Paul Muskee
    Original
  • M 101 LRGB, 



    
        

            Paul Muskee
    B
  • Final
    M 101 LRGB, 



    
        

            Paul Muskee
    C

B

Description: re-processed hoping that I could fix the stars... but no... will investigate further on new data sets, maybe something was wrong with this color data... I added Deconvolution to my workflow and used it on this image, the difference is subtle but very good nonetheless!

Uploaded: ...

C

Description: So I found a way to almost completely fix the issue with star colors. For that I used PixelMath with the following formula before applying a Star Mask: R/K: $T[0] G: iif(min($T[0],$T[2])>$T[1],min($T[0],$T[2]),$T[1]) B: $T[2] It is not perfect, but much better nonetheless. There will come a time where I will find the perfect solution :-).

Uploaded: ...

Sky plot

Sky plot

Histogram

M 101 LRGB, 



    
        

            Paul Muskee