I think the season for Cat’s Paw Nebula is closing. During the new Moon period in June, I collected images with the 1625 mm AT8RC because Cat’s Paw (NGC 6334) was high and I could get it from my backyard in Moore. My problem was that the Nebula is large (45 arc-min). Since my scope/camera combination has a 25 arc-min field of view (FOV) and I wanted some overlap, I was going to need a 6-panel mosaic. I decided that I didn’t have the patience for that and I tried to swap my 3" 760 mm Newtonian guide scope with the AT8RC prime scope. The FOV of the Newtonian was good for single image shots, but a 3" aperture in a Bortal 7 location was just plain discouraging. So, I ordered a 0.75 Reducer for the AT8RC.
In July, Cat’s Paw was at zenith by the time twilight ended. I did a fairly large set of 5-min images from my backyard trying to get the collimation and settings correct for the Reducer. At this point, I knew that I was committed to a 4-panel mosaic. This was good because I would have a high resolution image. This was bad because I was targeting 8 hours of integration time (32 hours of image collection time), and at this point in the season, I was only getting a 2 to 3 hours per clear-sky night. On the member night at CRO, I collected 1.6 hours under Bortal 3 conditions. This lead to a major integration faux-pas and a revelation that Bortal 7 wasn’t going to cut-it.
When night fell in August , the Nebula was well past zenith and 2 hours of collection was the most I was going to get. But the August new Moon period was great for clear skies; so, I setup at CRO and imaged every night for 7 straight. I was able to add 9 more hours of image collection time before the waxing Moon ran me off.
September will bring only an hour of collection time per night, which was why I said that the season was closing. So, I processed my collected subs, threw out 2 hours worth, which left me with a little more than 8 hours of image collection time. Yes, it was 4 times less than my goal – but I’ll take what I was given because it is better than I’ve done before.
Date: July & August, 2023
Location: Cheddar Ranch Observatory, Oklahoma
Camera: ZWO 183 MC Pro
Temperature: 0 C
Scope: 1214 mm - AT8RC using a 0.75 Reducer
Mount: Atlas EQ-G
Guider: QHY5L-II M
Guide Scope: 720 mm Meade Newtonian
Exposure: 300 seconds
No. of Subs: 9
Integration Time: 45 m
Resolution: 2132 x 1526 px
Original Resolution: 9456x5674 px
Software: Sequence Generator Pro, PixInsight, Adobe Photoshop