Category Archives: Comets

Comet NEOWISE on July 25, 2020

Comet Neowise on Jul 25, 2020. 47×4 sec @ ISO 1600, Canon T3, IDAS-LPS, Sigma Zoom 28-70 at 70mm, F/4, tripod mounted.

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 on Jul 25, 2020. 47×4 sec @ ISO 1600, Canon T3, IDAS-LPS, Sigma Zoom 28-70 at 70mm, F/4, tripod mounted.

Comet NEOWISE in the Evening Skies

Comet Neowise in the Clouds, Jul 23, 2020. Canon T3 camera on a tripod, IDAS-LPS and 18×4 sec @ ISO 1600 sub-images, Sigma 28-70 Zoom at 70mm, F/4.

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.

Comet Neowise in the Clouds, Jul 23, 2020. Canon T3 camera on a tripod, IDAS-LPS and 18×4 sec @ ISO 1600 sub-images, Sigma 28-70 Zoom at 70mm, F/4.

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.

Comet NEOWISE in the Morning Sky

Comet NEOWISE on July 9, 2020. 20 seconds of exposure using 8×2 sec and 1×4 sec sub-images. Canon T3 at ISO 400, Sigma 28-70 Zoom at 70mm, F/4. Camera on tripod. Taken from a metro location with Bortle 7 red zone light pollution levels.

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…

Comet NEOWISE on July 9, 2020. 48 seconds of exposure using 14×2 sec and 5×4 sec sub-images. Canon T3 at ISO 400, Sigma 28-70 Zoom at 70mm, F/4. Camera on tripod. Taken from a metro location with Bortle 7 red zone light pollution levels.

Imaging Session April 29, 2020

The Moon on Apr 29, 2020. Televue TV-85 at F/5.6, QHY183c, UHC-S filter.
Comet ATLAS (C/2019 Y4) on Apr 30, 2020 UT. 20×60 sec, Gain 30, Offset 15, QHY183c at -10C, UHC-S Filter, Televue TV-85 at F/5.6.
M81 & M82 Galaxies, 3hrs on Apr 29, 2020. 180×60 sec, Gain 30, Offset 15, QHY183c at -10C, UHC-S filter, Televue TV-85 at F/5.6.
M12 Globular Cluster on Apr 30, 2020. 70×60 sec, Gain 30, Offset 15, QHY183c at -10C, UHC-S filter, Televue TV-85 at F/5.6.

These are all the objects I managed to image on the night of Wednesday, April 29, 2020 and on into Thursday morning.  SharpCap 3.2 LiveStacking with dark and flat calibration plus dithering was used for acquisition.  Only minimal processing for all of these captures in Fitsworks and PS CS3.

I was trying not to waste a very clear evening after a storm had moved through earlier that day.  Not too bad, I guess.

Comet ATLAS (C/2019 Y4) Disintegration

Comet ATLAS on Apr 14, 2020, 03:42 UT. 20×30 sec, Gain 37, Offset 49, QHY183c at -20C, UHC-S Filter, Televue TV-85 at F/5.6.

Looks like Comet ATLAS was a dud.  It broke up into pieces after it had brightened much higher than predicted last month.  The brightening and breakup so soon afterwards indicates a large release of material from inside the object as it cracked open, so to speak.

By the time I took this pic, there were at least 3 to 5 major pieces in a line and the out-gassing of volatiles available was over with.   Just rock and dust was all that was left.

Comet ATLAS (C/2019 Y4)

Comet ATLAS (2019 Y4) on Mar 27, 2020, 3:05 UT. Base was 5×60 sec and I added another 10 minutes with 15 sec and 30 sec subs. QHY183c, UHC-S filter, TV-85 @ F/5.6.

I fought clouds on Mar 27, 2020 and also two nights before that on Mar 25, 2020.  The March 27th session produced this image.  The image data from the 25th was not worth posting.  This image, even though it is only a few minutes of exposure that I pieced together, was decent enough to post online.  Better than nothing, I suppose.

I am hoping that better conditions are coming soon.  I need to get a continuous set of  sub-images for this comet instead of having to put together a hodgepodge of exposures taken between bouts of cloud cover.

Comet C/2017 T2 PANSTARRS

Comet C/2017 T2 PANSTARRS. 14×30 sec, Gain 42, Offset 15, -20C, QHY183c, UHC-S filter, Televue TV-85 at F/5.6. Detail
crop.
Comet C/2017 T2 PANSTARRS. 14×30 sec, Gain 42, Offset 15, -20C, QHY183c, UHC-S filter, Televue TV-85 at F/5.6. Portrait crop.
Comet C/2017 T2 PANSTARRS. 11×180 sec, Gain 20, Offset 15, -15C, QHY183c, UHC-S filter, Televue TV-85 at F/5.6. Detail crop.
Comet C/2017 T2 PANSTARRS. 11×180 sec, Gain 20, Offset 15, -15C, QHY183c, UHC-S filter, Televue TV-85 at F/5.6. Full field crop.

Here is an image of a comet that is big and bright enough to make some interesting images, especially when it passes near objects like the Double Cluster.   I missed the closest approach of these two due to weather and other factors, but at least I got the parting shot of them together.

Comet C/2018 Y1 (Iwamoto) on Feb 13, 2019

C/2018 Y1 (Iwamoto) on Feb 13, 2019, 09:20 UT. 40×30 sec @ ISO 3200, IDAS-LPS, Canon T3, Televue TV-85 at F/5.6.

A new comet is in our neighborhood passing by at a relatively close 28 million miles from Earth.  It is a very long period comet that we have not seen before, but it has visited the inner solar system over 1300 years ago.  However, nobody noticed it because it was probably too dim to see naked eye.   It was discovered late last year by Japanese astronomer Masayuki Iwamoto.

Below is the Star-Streaks version with minimal processing.   Both images were treated minimally in these first iterations of processing.  There is probably room for improvement, but I doubt I’ll get much more than what I have here.

C/2018 Y1 (Iwamoto) on Feb 13, 2019, 09:20 UT. 40×30 sec @ ISO 3200, IDAS-LPS, Canon T3, Televue TV-85 at F/5.6.

I shot this from a Bortle Red/White zone in the middle of a metro area.   It was moving so fast that even 30 sec shots showed trailing.   So, I went with ISO 3200 and 30 sec exposures even though it trailed a bit, which was about max for the sky conditions I had this night.  I shot some 1 minute subs while trying to guide on the comet, but my DEC calibration was not working, so they showed some trailing in DEC.  Plus, I was barely able to pick it up with 4 sec subs, so it was not tracking too well at that setting.

These two didn’t come out too bad, I guess.   A darker location would have shown the tail better, probably and there is some hint of it here.  Reports are the comet can be seen in binoculars from dark sites, which is pretty good for any comet.   But, I knew from experience that when they are barely visible in binos from dark sites, binoculars are almost useless from inside a metro area, so I didn’t even try.