Comet Erasmus (C/2020 S3) on Nov 22, 2020, 4:50 AM to 5:40 AM. 50×60 sec sub-images captured in SharpCap 3.2, QHY183c at -20C cooling, Gain 20, Offset 200, Optolong L-eNhance filter, Televue TV-85 at F/5.6, dark, flat, bias calibration, Metro area, Bortle 7-8 zone, clear and average transparency, seeing was poor for comet elevation (under 12 degrees.) Star-Freeze version.
New comet discovered in September, 2020 in the morning sky at twilight. Very low and very hard to image from the metro area I’m in. I used an Optolong L-eNhance filter, which helped beat back the terrible LP I had to image through when it was less than 12 degrees above the horizon.
A very dark sky would have made quite a difference for this comet, but to me it is almost too small to be worthy of a trip to the boonies just for this guy. A runt comet. lol
This was taken from a Bortle 7-8 zone in a Metro area with the Optolong L-eNhance filter, my QHY183c camera and Televue TV-85 telescope.
It was moving very fast and exposures of two minutes showed slight trailing. I made a star-streaks version with some 3×5 minute simulated exposures and 4×3 minute simulated exposures. The actual sub-images were 30 seconds and SharpCap was used to LiveStack the simulated exposures. Here it is below:
This was taken before the 1st image, so you can see how far that sucker moved in the intervening time.
The evening of Jul 25, 2020 was supposed to be clouded out. It was at first, but for a short time, a sucker hole opened and I was able to get a batch of sub-images of Comet NEOWISE. The total was 57×4 sec shots, but only 47 of those would stack correctly, so a little over 3 minutes of exposure. Too bad it wasn’t totally clear. Oh well, it is what it is.
I guess I am lucky to even get images. July is the worst month for an evening comet here along the Gulf coast. We have thunderstorms galore in the afternoons and left-overs of them for hours afterwards and into the evenings.
I did do another rendition of the 47×4 sec data set. This time I aligned on the comet when stacking and it helped it come out better than before. Surprising how much it moved in the short exposure run vs the background stars, which you can see by how long the stars are elongated in this version and the comet is not:
Comet Neowise in between clouds, Jul 23, 2020. It was probably the best night weather wise since Comet Neowise moved to the evening skies, but still too cloudy to bring out my bigger scope. I used a Canon T3 on a tripod with a Sigma 28-70 Zoom for this session.
The top image is stacked with more adaptive noise reduction/rejection and the bottom was a straight additive stack to max out the dimmest parts. All subs were dark and offset calibrated.
Not too bad for being in a Bortle 7 Red Zone and using only an IDAS-LPS filter. But, I need to get to a dark sky location (and some better weather) before this thing passes me by! LoL! Soon, hopefully.
Clear skies, but muggy and lots of muck to shoot through with it that low. It was the clearest morning so far since the comet became visible. That’s a dirt pile in the foreground, btw and not a mountain. LoL!
Below is an image that is a reprocess job on the data with a different color balance, slightly more sub-images and tighter cropping. I also did dark and offset calibration to try and reduce noise.
I was hoping it would come out better than the first one, but since conditions were sub-par to begin with, I guess I will just have to wait until it gets in the evening skies to get a better shot. Oh, well…
Images of Comets, Nebulae, Galaxies and Star Clusters