Category Archives: Comets

Feb 24th/25th Imaging Sessions

The February Full "Snow" Moon of 2024. AT60EDP, QHY294C, Antlia Triband filter.  The best 20 frames of 45, stacked in AutoStakkert.   1.5x enlarged crop.
The February Full “Snow” Moon of 2024. AT60EDP, QHY294C, Antlia Triband filter.  The best 20 frames of 45, stacked in AutoStakkert.   1.5x enlarged crop.

I normally don’t image during a full moon, but the weather was beautiful and I had a new telescope to do more testing with.    Plus, there was a comet just begging me to take it’s picture.   I couldn’t pass up the chance.

I ended up taking images both Saturday and Sunday nights.   I tried to give lots of time to single objects and not jump around so much, for a change.

Comet 12P/Pons-Brooks on Feb 25, 2024 (Feb 26 UT.)   17×60 sec, QHY294C, AT60EDP at F/5, Antlia Triband filter.  Full field.
Comet 12P/Pons-Brooks on Feb 25, 2024 (Feb 26 UT.)   17×60 sec, QHY294C, AT60EDP at F/5, Antlia Triband filter.  Star Freeze cropped version.
Comet 12P/Pons-Brooks on Feb 25, 2024 (Feb 26 UT.)   17×60 sec, QHY294C, AT60EDP at F/5, Antlia Triband filter. Star Streaks cropped version.

The comet was very low in the west at dusk.  I had to quickly get shots and didn’t notice a building’s awning was in the shot along with street lights casting reflections from that direction.   Clouds coming and going didn’t help, either.

But!   This comet is bright enough to show up (with a tail!) that low in the muck of a Bortle 8-9 zone!    That’s quite bright, by most comet imaging standards!

IC 446. 79×180 sec, QHY294C, Antlia Triband filter, AT60EDP at F/5.
Cone Nebula area. (IC446 is on the right.)  This is only 12 x 3 minute sub-mages. AT60EDP, QHY294C, Antlia Triband filter.
Cone Nebula area. (IC446 is on the right.)  This is only 12 x 3 minute sub-mages. AT60EDP, QHY294C, Antlia Triband filter.

The Cone and the IC 446 Nebula area.   It was well placed and I shot 4 hours for IC446 on one night and did a short run on the Cone next door the following night.

M13 Globular Cluster. 50x 3 minutes, QHY294C, AT60EDP at F/5, Antlia Triband RGB Ultra filter.
M13 Globular Cluster. 50x 3 minutes, QHY294C, AT60EDP at F/5, Antlia Triband RGB Ultra filter.

I always enjoy seeing M13 again after it emerges in the late winter morning skies high enough to get imagery.   The colors got washed out with all the moonlight, unfortunately.   I created a darker version with more color enhancement, but the washed out look remains:

M13 Globular Cluster. 50x 3 minutes, QHY294C, AT60EDP at F/5, Antlia Triband RGB Ultra filter. Darker version.
M13 Globular Cluster. 50x 3 minutes, QHY294C, AT60EDP at F/5, Antlia Triband RGB Ultra filter. Darker version.

Oh, well…  I had fun taking it and processing it.   🙂

First Light – Astro-Tech AT60EDP

The Orion Nebula on 2/20/24. 68x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60EDP at F/5. Full Field.
The Orion Nebula on 2/20/24. 68×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60EDP at F/5. Full Field.
The Orion Nebula on 2/20/24. 68x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60EDP at F/5.
The Orion Nebula on 2/20/24. 68×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60EDP at F/5.  Cropped.

Here’s the very first stacked image taken with my new Astro-Tech AT60EDP.  It’s a 60mm, F/5 Petzval telescope with 300mm focal length.   This  was 64×180 sec using the new scope.   Location was a Bortle 8-9 zone with a bright moon out, 48F,  clear and above average transparency.   The second version is the full field.

Comet 62P/Tsuchinschan in the Virgo Cluster. 68 x 180 sec, QHY294C at -10C, Astro-Tech AT60EDP at F/5, Antlia Triband RGB Ultra filter.
Comet 62P/Tsuchinschan in the Virgo Cluster. 68 x 180 sec, QHY294C at -10C, Astro-Tech AT60EDP at F/5, Antlia Triband RGB Ultra filter.

Comet 62P/Tsuchinschan near the galaxies NGC 4608, NGC 4596. Also included are M58, M59, M60 and other faint galaxy fuzzies in the Virgo Galaxy Cluster.

M4 Globular Cluster. 11 x 3 minutes with a QHY294C, Antlia Triband RGB Ultra filter from a Bortle 8-9 zone.
M4 Globular Cluster. 11 x 3 minutes with a QHY294C, Antlia Triband RGB Ultra filter from a Bortle 8-9 zone.

M4 Globular Cluster, Antares and friends in Scorpio. It was still the 1st light night for my new AT60EDP, but at 5:00 AM the next morning.  This is 11 x 3 minutes with a QHY294C, Antlia Triband RGB Ultra filter from a Bortle 8-9 zone.  Still noisy with only 33 minutes and there was some twilight, but I’m sure I’ll be able to add to it in time.

The Moon, A Comet and A Star Cluster – Jan 28th, 2024

Comet 144P/Kushida. 15x180 sec, AT60ED, QHY294C, Antlia Triband filter.
Comet 144P/Kushida. 15×180 sec, AT60ED, QHY294C, Antlia Triband filter.
Comet 144P/Kushida. 15x180 sec, AT60ED, QHY294C, Antlia Triband filter. Star Freeze version.
Comet 144P/Kushida. 15×180 sec, AT60ED, QHY294C, Antlia Triband filter. Star Freeze version.

It was a clear Sunday evening on Jan 28th, 2024 and I had to do some tweaking to the scope, so I took advantage of the good weather and did some imaging to test the results.

After the tweaks and adjustments for the scope, I went straight to Comet 144P/Kushida, which was well placed in the early evening sky.   I took 45 minutes worth of subs and above are the two images I generated from this data.

M35 Open Cluster and NGC 2158, taken on Jan 28th, 2024. 40x180 sec, QHY294C, Astro-Tech AT60ED, Antlia Triband filter.
M35 Open Cluster and NGC 2158, taken on Jan 28th, 2024.  40×180 sec, QHY294C, Astro-Tech AT60ED, Antlia Triband filter.

I shot of few sub-images of M35 the last time I was out and wanted to return to it now that I tweaked the scope.   I got two hours of data on it and it came out reasonably well.

By the time I finished M35, the moon had risen high enough to drown out any dim nebulae and whatnot, so I shot the moon itself.   It was still rather low in the sky, but did not come out too bad:

The Moon on Jan 28, 2024. QHY294C, Astro-Tech AT60ED, Antlia Triband filter.
The Moon on Jan 28, 2024. QHY294C, Astro-Tech AT60ED, Antlia Triband filter.

I resized it 200% for this display image and did some sharpening with the AstraImage Maximum Entropy Deconvolution filter in PS.  Yes, not too bad at all for a 60mm scope.

Saturday Night, January 13th-14th, 2024

Comet 144P/Kushida. 5x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.
Comet 144P/Kushida. 5×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.
Comet 144P/Kushida. 5x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.
Comet 144P/Kushida. 5×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.

On this night, I was mainly going to try making adjustments to the new tilt plate gizmo for the AT60ED and see if I could get further improvements to its field.   Even though it was clear at first, the forecast was clouds coming in for a few hours, so I was not looking to take any keeper images and I wanted to get this testing done instead.

I had just completed star aligning and noticed a comet near Aldebaran in Taurus on the charts, which I had just used to sync the scope’s alignment with.   It wasn’t listed by SkyHound’s Comet Chasing website, so I took a few images to see what it looked like and how bright it was.    Only 15 minutes of exposure, so it’s not much, but it is what started the night.

I was really after the Comet 62P in Leo, and this runt comet was interesting, but I wanted to do more testing of the tilt plate thingy.   I was going to come back to it, but clouds invaded and stayed until 11:00 PM or so.   By that time, I still had about 2 hours for the comet in Leo to get to a good spot, so I took images of M81 and M82 to kill time.

M81 & M82. 36x180 sec, QHY294C, Antlia Triband filter, AT60ED at F/4.8.
M81 & M82. 36×180 sec, QHY294C, Antlia Triband filter, AT60ED at F/4.8.

I lost/missed focus for this dataset and the guiding for it was terrible.    Plus, it wasn’t quite as clear as it needed to be from lingering clouds and moisture.  I salvaged what I could.   I only include it here to remind me to focus before each object if I want a keeper image and remind me it takes 3 SharpCap polar alignments and not just 2 to get good tracking.

Finally, 62P Tsuchinshan is high enough to image, so I star taking images of it.   I realized the first few subs were not in focus, so I stopped and redid it.  But otherwise, I was able to let it take pictures on its own while I caught a few winks.   All in all, 68 images of it were taken or 3.4 hours worth:

Comet 62P Tsuchinshan on Jan 14, 2023. 68x180 sec, QHY294C at -10C, Antlia Triband filter, AT60ED at F/4.8
Comet 62P Tsuchinshan on Jan 14, 2023. 68×180 sec, QHY294C at -10C, Antlia Triband filter, AT60ED at F/4.8

Transparency was only average to slightly above at times for this night, so it wasn’t as clear as predictions.  But, I did notice what the focus was doing and I now have a better handle on it.  Plus, now that I know about it, I might have to try for more sub-images on that first comet and see what shakes out.

Mid-Week Imaging Session Jan 9th/10th, 2024

The Flaming Star and Tadpoles Nebulae area. 75x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.
The Flaming Star and Tadpoles Nebulae area. 75×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.
The Flaming Star and Tadpoles Nebulae area. 75x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8. Lighter version.
The Flaming Star and Tadpoles Nebulae area. 75×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8. Lighter version.

In the second week of 2024, the weather gave me a break on a Tuesday evening.  It was going to be one really clear and totally transparent night and I could not let it pass without imaging something.

I was setup and was taking flats by dusk.   But, the object I really wanted to get data on was not going to be in position until about 2:00 AM the following morning.  So, I needed to kill time and this area of the sky in the image above (Auriga) was in prime position.  I managed to get 3.75 hours before the mount reached the meridian and it was time to flip it.

The Virgo Cluster and Mankarian's Chain area. 40x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.
The Virgo Cluster and Mankarian’s Chain area. 40×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.

At this point, I had another 2 hours of waiting, so instead of flipping the mount, I went with imaging the Virgo Cluster with this very wide field rig.   Not too bad for only two hours, but it needs about double what I had time for.

Comet 62P/Tsuchinshan, Jan 10th, 2024.   45x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.
Comet 62P/Tsuchinshan, Jan 10th, 2024. 45×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8.

Finally, Leo and Comet 62/P, the object I was really after, was high enough to get data on, and I managed 45 sub-images of it.  I have two versions.  One is the cropped version above that I did first.

The full field version is below, which I restacked a couple of times to get a better background-stars-only image.  One stack was done with SharpCap, and then I re-calibrated the subs in FitsWorks and stacked them again in IRIS, which was not as noisy as the Sharpcap stack.  These two stacks were combined and then the comet-only images was composited in.

Not a very big comet, but it has a tail, at least.   I don’t think it will get much better than this, unfortunately.   It already passed perihelion in December and will make the closest approach to Earth before month’s end.  It was forecast to slowly dim over the next few weeks.

Comet 62P/Tsuchinshan, Jan 10th, 2024. 45x180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8. Full field version.
Comet 62P/Tsuchinshan, Jan 10th, 2024. 45×180 sec, QHY294C at -10C, Antlia Triband filter, Astro-Tech AT60ED at F/4.8. Full field version.

I stopped imaging the comet shortly before dawn.  I had to work that day, so I grabbed my scope and laptop and brought them in and tried to sleep for an hour or so.   I had napped during the night, but still lacked enough sleep to function.  It took a couple of days to recover enough to do the processing for these.  lol

Night of December 10th/11th, 2023, Sightseeing Tour

The only serious image out the bunch was the Soul Nebula.   It was the only one I planned for and was my main target.  I managed to get 3.8 hours on it, with .8 hr on one side of the peer and the other 3 hrs on the other.  BTW, all images were taken with a QHY294c, a UHC-S filter and a AT60ED on a SkyWatcher GTi goto mount in Bortle 7-8 skies.

Soul Nebula – 76x180sec,Gain1600

The rest of the images were mostly done with 30 sec exposures at high gain (i.e., 3000. I normally keep it at 1600.)  Like I said, I was sightseeing and doing an EAA experiment.

The Elephant’s Trunk Nebula area was the longest of the 30-sec shots, 240 x 30 seconds.  I still had to combine it with about 30% blend of a 90 minute exposure taken with another camera, but the same scope.  It was still too noisy even after 240 subs.

Elephant’s Trunk – 240×30 sec, (plus 30×180 sec at 30% blend.)

So, the 30 sec high gain experiment for EAA type imaging is not up to par with what I could do with the QHY183c camera.   It did well on open clusters, at least.  Oh, well.  Live and learn, as they say.

Comet 12P – 72×30 sec
M67 – 60×30 sec
Seagull Nebula – 28×30 sec
M44 – 93×30 sec

First Images of Comet 12P/Pons-Brooks

Comet 12P/Pons-Brooks on Nov 19, 2023. 50×30 sec, QHY294C at -10C, UHC-S filter, Astro-Tech AT60ED at F/4.8.
Comet 12P/Pons-Brooks on Nov 19, 2023. 50×30 sec, QHY294C at -10C, Gain 3551, Offset 50, UHC-S filter, Astro-Tech AT60ED at F/4.8.

It was the first clear night since the last session on Nov 3rd.   I wanted to see this comet and try to get images of the Heart Nebula.  The comet was first in line since it was already getting low in the west after sundown.    I forgot to adjust the gain down and shot it at the highest gain setting I usually use when focusing and star aligning.  Surprisingly, I was able to salvage the sub-images and get a usable image from them.   BTW, the comet seems to have a tail, but it could be an artifact of the gain setting or something.

The Orion Nebula Region. 7 x 180 sec, QHY294C at -10C, UHC-S filter, Astro-Tech AT60ED at F/4.8.
The Orion Nebula Region. 7 x 180 sec, QHY294C at -10C, UHC-S filter, Astro-Tech AT60ED at F/4.8.
M46 and M47 on Nov 19, 2023. 5×180 sec, QHY294C at -10C, UHC-S filter, Astro-Tech AT60ED at F/4.8.

Next up, I did a quick look see at M42 and the M46/M47 Open clusters area.   I wasn’t planning on keeping these, but the data on my main target of the night, the Heart Nebula, was horrible.  So, I thought better of just ditching these sub-images.

Cone Nebula Area. 10x180 sec, QHY294C at -10C, Gain 1600, Offset 50, UHC-S filter, AT60ED at F/4.8
Cone Nebula Area. 10×180 sec, QHY294C at -10C, Gain 1600, Offset 50, UHC-S filter, AT60ED at F/4.8
M78 in Orion. 7x180 sec, QHY294C at -10C, Gain 1600, Offset 50, UHC-S filter, AT60ED at F/4.8
M78 in Orion. 7×180 sec, QHY294C at -10C, Gain 1600, Offset 50, UHC-S filter, AT60ED at F/4.8
M44 in Cancer. 4x180 sec, QHY294C at -10C, Gain 1600, Offset 50, UHC-S filter, AT60ED at F/4.8
M44 in Cancer. 4×180 sec, QHY294C at -10C, Gain 1600, Offset 50, UHC-S filter, AT60ED at F/4.8

I also did a short run on the Cone Nebula/Christmas Tree Cluster area of 10 x 3 minutes, plus I got a few frames of M78 and M44.   The Cone area is not too bad considering it is only 30 minutes of time.  M44 was a very quick look and I just wanted to see how it would fit with this rig I was using.   But, M78 needs a couple of hours to even begin to look nice and I only got 21 minutes worth.  Oh, well… next time.

The Heart Nebula. 56x180 sec (nebula,) 18x180 sec (stars,) QHY294C at -10C, Gain 1600, Offset 50, Baader UHC-S filter, Astro-Tech AT60ED at F/4.8.
The Heart Nebula. 56×180 sec (nebula,) 18×180 sec (stars,) QHY294C at -10C, Gain 1600, Offset 50, Baader UHC-S filter, Astro-Tech AT60ED at F/4.8.

And, finally, here is the salvage job on the Heart Nebula, of which I had two sets of data.  One was slightly out of focus, the other had a terrible gradient from an IR source that was pointed right at the lens and I think some of it got through the UHC-S filter, or it was a reflection off the front glass.

What I ended up doing is taking the slightly out of focus stars and removing them totally, then taking the good stars from the data that had the bad gradient and combining them.   Still noisy and not that great, but reducing it to 33% smoothed it out enough to pass as a display image.

Oh, well.  Another reshoot for this one is in order and also for its close neighbor, the Soul Nebula.

Imaging Session – Friday, March 3rd, 2023

It was a Friday night, March 3rd/4th, clear and cool.  The Moon was out at 83% full.  So, I thought it would be a perfect night to test the Antlia Triband RGB Ultra filter in moonlight conditions to see how bad that would affect it and to get an update on how Comet C/2022 E3 was doing.

Comet C/2022 E3 (ZTF). 32×120 sec, QHY294C-Pro, Unity Gain, Offset 60, Antlia Triband RGB Ultra filter, Televue TV-85 at F/5.6.

Well, the comet’s photogenic appearance has diminished quite a bit since I last imaged it in mid-February.  The filter I used probably attenuated the brightness, but by the size in this full field image you can see the comet is much further away from us and receding into the distance fast.  Oh, well.  It was fun while it lasted.

Orion Nebula Complex. 83×15 sec, QHY294C-Pro, Antlia Triband RGB Ultra filter, Televue TV-85 at F/5.6.

Next up, I did some EAA-type imaging to test short exposures with the filter on a bright object like M42.   It worked pretty good for such a short time (83×15 sec or 20 minutes) of exposure.   But, it would need quadruple that time to get right and I was more interested on using longer exposures that would bring out dimmer nebulae better.

So, I switched to the nearby Horse Head Nebula and Flame to test the filter with one minute exposures.  I refocused first since M42 looked out of focus and glad I did since it was way off.

The Horse Head and Flame were a better choice for the amount of moonlight out and a better test of the filter’s ability to pick up H-Alpha nebula light.   I thought it came out good for only 40 subs:

Horse Head Nebula. 40×60 sec, QHY294C-Pro, Antlia Triband RGB Ultra filter, Televue TV-85 at F/5.6.

When Orion and all the good objects there got out of position and got into the power lines, I moved further east to get more of the Rosette Nebula, which I imaged a few weeks prior.  It was also closer to the moon and had a strong gradient due to moonlight and the vignetting my imaging train has.  I managed to minimize it in post processing, but it was not exactly easy.    After processing, this is the 60 x 60 sec of exposure with the Triband filter I managed to get:

Rosette Nebula with Triband Filter. 60×60 sec, QHY294C-Pro, Televue TV-85 at F/5.6.

I combined that with the data I previously had that was taken with just a clear UV/IR cut filter:

Rosette Nebula, 10×180 sec plus 60×60 sec, QHY294C-Pro, Televue TV-85 at F/5.6.

Not too bad of a mixture.  After these runs, I moved to the east and tried imaging a few things there, but the moonlight and LP on that side was more than what the filter could deal with, it seems.

I imaged M101, but the gradient was severe and the image was very difficult to flatten all of that gradient out and preserve the dim areas.   By the time I got rid of it all, the colors were drained out and no amount of saturation adjustments were going to bring them back.

M101 Pinwheel Galaxy. 163×60 sec, QHY294C-Pro, Televue TV-85 at F/5.6. Antlia Triband RGB Ultra filter test.

So, tried my luck on the M13 Globular Cluster, which was a good test for the Antlia.   Still had a strong gradient to deal with, but since it has no nebula parts, it was much easier to get rid of:

M13 Globular Cluster. 75 x 60 sec, QHY294C-Pro, Televue TV-85 at F/5.6.
M13 Globular Cluster. 75 x 60 sec, QHY294C-Pro, Televue TV-85 at F/5.6. Full field.

 

The Comet From Last Night – Feb 18, 2023, 1:09 – 2:30 UT

C/2022 E3 (ZTF on Feb 18, 2023, 01:09 to 03:36 UT. 12×300 sec plus 40×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6.
C/2022 E3 (ZTF on Feb 18, 2023, 01:09 to 02:30 UT. 40×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6.
C/2022 E3 Comet-Only after stacking in IRIS.

Another comet image to add to my collection.  This is perhaps the last image from me of C/2022 E3 ZTF for perhaps the next 2 weeks.   Weather forecast is nothing but clouds next 10 days or more.    By that time, the moon will getting full and the comet is rapidly shrinking in size and fading in brightness.   It will still be around, just not as photogenic as it is now.

Also on this night, I tried out a new filter – the Antlia Triband RGB Ultra Filter.  Boy, that’s a weird one, let me tell you.  Blue as blue can get.  lol.   But, a stack from SharpCap color balances out in IRIS when setting the blackpoint, so I don’t know?  SharpCap refuses to color balance it and leaves it too blue, however.     lol    So, I just stack and then process first in IRIS for initial color.

This object(s) below was the second or third test subject.  Perfect, since this is in strong LP on the north to northwest side.  If it can block that, great!  And it seems to have blocked it:

M81 and M82 galaxies. 42 x 3 minutes, QHY294C-Pro at -10C, unity gain, offset 60, Televue TV-85 at F/5.6. New filter test: Antlia Triband RGB Ultra Filter.

Yes, it has funky colors, but they’re mostly there, instead of that dull pasty look from duo-band filters.  I don’t know?  I’ll have to do more testing.

Thor’s Helmet was the first object I used it on.  I shot it with a UV/IR then with the Antlia Triband with roughly the same framing.   This is just the subs-images using the Antlia.  It is about 33 minutes of combined exposure:

Thor’s Helmet. 11 x 180 sec, QHY294C-Pro at -10C, Antlia Triband filter, Televue TV-85 at F/5.6.

Finally, after experimenting with Thor’s Helmet, I went to one of the tougher targets – the Virgo Cluster.  Its always either not enough exposure or the wrong colors with duo-band and UHC filters for this cluster.  But, does this filter have the blue and enough other colors to give it what it needs?   Well, here it is:

Virgo Cluster 29 x 5 minutes, QHY294C-Pro at -10C, Antlia Triband RGB Ultra filter, unity gain, offset 60, Televue TV-85 at F/5.6.

Comet C/2022 E3 (ZTF) on Feb 13, 2023 UT

Comet C/2022 E3 (ZTF) on Feb 13, 2023, 02:55 mid-exposure. 68×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6. Portrait version.
Comet C/2022 E3 (ZTF) on Feb 13, 2023, 02:55 mid-exposure. 68×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6. Landscape version. North is down.

High clouds and dew plagued my imaging session on this night. My dew heater’s power supply failed right at the start, too.

For this full field image, I took 40 sub-images of the comet between 01:49 and 03:09 UT and another 31 subs between 03:19 and 04:21 UT . I only lost 3 subs to guiding problems, despite the clouds.

I thought all the clouds and dew problems I had would ruin the chances of getting a good final image, but I guess I was wrong. 🙂

Technical: 37×120 sec, QHY294C-Pro at -10C, Gain 1600 (Unity,) Offset 30, UV/IR filter, Televue TV-85 at F/5.6, Atlas EQ-G w/EQMOD. PHD2 Guiding, SharpCap 4.x LiveStacking for acquisition, FitsWorks for dark/flat calibration and debayering, IRIS for stacking and PSCS3 for post-processing.

An earlier, more gaudy version with only 37 sub-images:

Comet C/2022 E3 (ZTF) on Feb 13, 2023, 02:30 mid-exposure. 37×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6. Portrait version.
Comet C/2022 E3 (ZTF) on Feb 13, 2023, 02:30 mid-exposure. 37×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6.

c2022e3-2023-02-13-0230UT-37×120-qhy294c_-10C-ug-o30-uvir-85f5_6-v2a