Hemisphere:  Northern  ·  Constellation: Lynx (Lyn)
Getting plate-solving status, please wait...
PuWe1 (Purgathofer-Weinberger 1), 


            Chris Sullivan
PuWe1 (Purgathofer-Weinberger 1)
Powered byPixInsight

PuWe1 (Purgathofer-Weinberger 1)

Getting plate-solving status, please wait...
PuWe1 (Purgathofer-Weinberger 1), 


            Chris Sullivan
PuWe1 (Purgathofer-Weinberger 1)
Powered byPixInsight

PuWe1 (Purgathofer-Weinberger 1)


Imaging Telescopes Or Lenses
Explore Scientific 80mm Carbon Fiber Air-Spaced Triplet ED APO Refractor · Explore Scientific PN-208/812 Carbon Fiber OTA
Imaging Cameras
ZWO ASI1600MM Cool · QHY-CDD 183C Beta
SkyWatcher AZ-EQ5
Orion SkyGlow 2" Astrophotography Filter · ZWO H-alpha 7nm · OIII
Explore Scientific HR Coma Corrector · Orion 0.8x focal reducer/flattener
Guiding Telescopes Or Lenses
Solomark F50 50mm guidescope
Guiding Cameras
ToupTek ToupCam GCMOS01200KPB

Acquisition details

Oct. 11, 2017 ·  Oct. 17, 2017 ·  Oct. 18, 2017 ·  Oct. 19, 2017 ·  Oct. 20, 2017 ·  Oct. 21, 2017 ·  Oct. 22, 2017 ·  Oct. 25, 2017 ·  Oct. 27, 2017 ·  Oct. 28, 2017 ·  Oct. 31, 2017 ·  Nov. 1, 2017 ·  Feb. 3, 2018
OIII: 152x400" (16h 53' 20") (gain: 225.00) bin 2x2
OIII: 76x600" (12h 40') (gain: 225.00) bin 2x2
Orion SkyGlow 2" Astrophotography Filter: 94x60" (1h 34') (gain: 10.00)
ZWO H-alpha 7nm: 151x300" (12h 35') (gain: 225.00) bin 2x2
ZWO H-alpha 7nm: 116x400" (12h 53' 20") (gain: 225.00) bin 2x2
ZWO H-alpha 7nm: 34x600" (5h 40') (gain: 225.00) bin 2x2
62h 15' 40"
Avg. Moon age:
13.19 days
Avg. Moon phase:
Bortle Dark-Sky Scale:

Basic astrometry details

Astrometry.net job: 2349133

RA center: 06h19m30s.2

DEC center: +55°3632

Pixel scale: 0.608 arcsec/pixel

Orientation: 83.218 degrees

Field radius: 0.737 degrees

Resolution: 7150x5000

Data source: Backyard


I've had PuWe 1 on my list since I first found out about it in February and it's been at the top of my list ever since. I knew it was faint, so HFG1/Abell6 served as a kind of practice run for this. But I was not prepared. This was excruciatingly difficult. Ha was only barely visible on 400 second subframes and OIII was only visible in stacks. Even now, I still don't think I got enough OIII signal, but I think the only way to improve on that would be darker skies or 3 nm filters, neither of which I have at the moment. Part of me wants to say "never again". The other part of me is thinking 'maybe if I had a really sensitive CCD, a Tak Epsilon, Hyperstar or RASA and a second mount...' (so I guess that does mean 'never again?'). This image marks the first time I've done anything with PixInisght, however, it was only noise reduction. It's still terribly noisy, though, but man is PixInsight difficult! At any rate, I guess this means I'm in the process of learning how to use PI now, so expect more revisions, especially since it's a lot noisier than I was hoping it would turn out. However, I'm still not sure I can extract anything else out of this. The OIII in particular was ridiculously weak.

Special thanks to Horst Ziegler, Frank Iwaszkiewicz and Bob Andrews who all gave me some invaluable pointers on this as well as J-P Metsavainio for sharing his tone mapping process, which made this possible. It never would have been published without it - tone mapping enabled me to really overstretch the OIII.