Category Archives: Comets

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

Comet Imaging on Feb 9th/10th, 2023

C/2022 E3 (ZTF) on Feb 10, 2023, 03:43 UT. 15×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
C/2022 E3 (ZTF) on Feb 10, 2023, 01:30 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
C/2022 E3 (ZTF) on Feb 10, 2023, 01:30 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.

It was a clear Thursday afternoon and early evening, Feb 9th, 2023 (Feb 10th in Universal Time after 6pm here in Cajun Country,) when I tried to image Comet C/2022 E3 (ZTF) again.   The clearing didn’t last long, however.  Clouds interrupted and got into many of the sub-images.  In one case of 30+ sub-images, half had to be eliminated.

But, what I did manage to get was good enough to produce several star-freeze versions and at least one star-streaks version of the comet on this night.  Plus, as a bonus one more deep sky object.

C/2022 E3 (ZTF) on Feb 10, 2023, 01:30 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
C/2022 E3 (ZTF) on Feb 10, 2023, 03:37 UT. 31×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
C/2022 E3 (ZTF) on Feb 10, 2023, 01:21 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.

 

This one was processed as an arcsinh (color) stretch that seems to work for this exposure and didn’t with other stacks.    This is the same data as the above image, btw.   Different take and look.

C/2022 E3 (ZTF) on Feb 10, 2023, 01:21 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.

 

I had good luck on the Rosette for a short run from about 11:30 PM till midnight, which is when the moon rose.  The data was good and cloud free.  Despite the lack of exposure, it was adequate enough to get this level of a display image:

First Light – New QHY294C-Pro Camera

With a very nice comet in the sky, I decided it was time to break down and get the camera I’ve wanted since the advent of the CMOS cooled-camera revolution.  It’s the QHY294C-Pro, an 11MP camera with low noise, 14bit output and a larger chip than the QHY183c.

I immediately noticed how much less noise it has than the old CMOS camera and how sensitive it is.   I should have got this one in the beginning.

A quick test was done on the Orion Nebula region for 30 minutes of exposure.   It came out better than some of my hours long attempts with the old camera or my DSLR.  Plus, the nearly full moon was out and produced a very harsh gradient and strong vignetting.   The flat I used was for a different orientation of the camera, so it did not fully remove the vignetting, but it got all the dust motes that were on my UV/IR filter and sensor cover.   (I should have blew off the dust on both before starting out, I guess.  lol)

I cropped the image above down a bit.   Here’s another version with different color balance and it is the full field, uncropped original:

First light image – The Orion Nebula and Running Man Nebula. 60×30 sec, Unity Gain (1600,) Offset 60, QHY294C-Pro, UV/IR filter, Televue TV-85 at F/5.6 (480 mm.)

BTW, no dark calibration in the above image.   It was a straight raw stack.   I covered the scope after the above test and shot darks in prep for what I was really after.

This was my main target, Comet C/2023 E3 ZTF.   It was highest in the sky at 8:30 PM local time and I started imaging it right before that.   I spent several hours on it, but this image is just the first 1.5 hours of that time.

BTW, my friends at Televue Optics, Inc., liked the above comet image enough to use it on their blog.  The post is about comet imagers using Televue equipment for their shots.  It is linked here: Televue Optics Blog – Comet C/2022 E3 (ZTF) Imagers

Here’s another version with a less red background color from the moon’s interference:

Comet C/2022 E3 (ZTF) on Feb 4th, 2023, 2:30-4:00 UT. 107 x 60 sec at unity gain, offset 60, QHY294C-Pro, UV/IR filter, Televue TV-85 at F/5.6.

A nearly full moon was out and in the same quadrant of the sky as the comet.  Moonlight this bright is tough to deal with and creates some very harsh gradients.   Luckily I took some flats the next morning and was able to use them to help minimize that issue.

NGC 4565 Edge-On Galaxy. 222 x 60 sec at unity gain, offset 60, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
M83 Southern Pinwheel Galaxy. 95 x 60 sec at unity gain, offset 60, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.

Last but not least, were two galaxies I imaged to test the resolution and sensitivity of the new camera.  The image scale lacks for galaxies, but the color and low noise were outstanding.

Remember, all of these were taken on a bright moonlit night a day or so before full moon.   I would say the first light test was a major success!

Comet C/2022 E3 ZTF on Jan 27, 2023

Comet C/2022 E3 ZTF. 175×60 sec, gain 20, offset 32, UHC-S filter, QHY183c at -20C, TPO/Askar 40mm F/4.5.
M78. 8×60 sec at gain 30, offset 17, QHY183c at -20C, TPO/Askar 40mm F/4.5. Moon inserted for scale.

Another good night for imaging.   I had great luck on the comet, but not much luck with a two nebula and only so, so with another.

California Nebula. 30×60 sec, gain 20, offset 32, UHC-S filter, QHY183c at -20C, TPO/Askar 40mm F/4.5.

I missed focus on the California Nebula.  Salvaged what I could for this display image.   It is on my list for a do over.

M78 (again.) 101×60 sec, gain 20, offset 32, UHC-S filter, QHY183c at -20C, TPO/Askar 40mm F/4.5.

Still not enough time for M78.  It needs 3 or more hours and with a comet around, it is not getting it until the comet is gone.  lol

The Belt of Orion. 110×60 sec, Gain 20, Offset 32, UHC-S fitler, QHY183c at -20C, TPO/Askar 40mm F/4.5.

Last on the list is the Belt of Orion.  I had a little more luck with this one than the others.   It too could use more time, however.

 

 

Comet C/2022 E3 (ZTF) on Jan 23, 2023

Comet C/2022 E3 ZTF. 16×300 sec @ gain 11, offset 17, QHY183c at -15C, UV/IR Filter, TPO/Askar 40mm F/4.5.

Comet C/2022 E3 was where Earth was passing through the comet’s orbital plane and we got to see a strong anti-tail during the passage.

While waiting on the comet, I imaged a few nebula.  None of them serious attempts.

The Witch Head Nebula. 22×300 sec, gain 11, offset 17, QHY183c at -20C, UV/IR filter, TPO/Askar 40mm F/4.5.
M78. 8×60 sec at gain 30, offset 17, QHY183c at -20C, TPO/Askar 40mm F/4.5.

Friday the 13th Imaging Session

Normally I avoid doing anything on Friday the 13th.  lol.  But, since astronomical time is Greenwich Mean Time, the 13th ended at 6:00PM CST, so I was good.  Ha!

The Orion Nebula and Friends. 37×2 (core,) 22 x 300 sec, Gain 11, Offset 17, QHY183c at -20C, Astronomic L-3 UV/IR filter, TPO (Askar) 180mm, F/4.5.

I imaged 3 objects this night. One was the object above, the Orion Nebula (and friends,) one was the Flaming Star Nebula and I shot about 2.5 hours of Comet C/2022 E3 (ZTF.)

Equipment used was an Askar 180mm F.L., F/4.5 scope (40mm objective,) an Astronomic L-3 UV/IR filter and a QHY183c camera, and an Atlas EQ-G with EQMOD.

Here’s the Flaming Star. I missed the focus on this. I threw away several processing attempts before salvaging what I could for this display image. Oh, well… next time.

The Flaming Star Nebula (and friends.) 33 x 300 sec, Gain 11, Offset 17, QHY183c at -20C, Astronomic L-3 UV/IR filter, TPO (Askar) 180mm, F/4.5.

Next, after waiting till 2:30-3:00 AM, I took images of Comet C/2022 E3 (ZTF).   It is small and still kind of dim, but has a long, faint tail.  I have two data sets  with about an hour each of exposure.

Star Freeze version of Comet C/2022 E3 (ZTF). 11×300 sec, guided on the comet, Gain 11, Offset 17, QHY183c at -20C, Astronomic L-3 UV/IR filter, TPO (Askar) 180mm, F/4.5.
Star Streaks version of Comet C/2022 E3 (ZTF). 11×300 sec, guided on the comet, Gain 11, Offset 17, QHY183c at -20C, Astronomic L-3 UV/IR filter, TPO (Askar) 180mm, F/4.5.
tar Freeze version of Comet C/2022 E3 (ZTF). 12×300 sec, guided on the comet, Gain 11, Offset 17, QHY183c at -20C, Astronomic L-3 UV/IR filter, TPO (Askar) 180mm, F/4.5.
Star Streaks version of Comet C/2022 E3 (ZTF). 12×300 sec, guided on the comet, Gain 11, Offset 17, QHY183c at -20C, Astronomic L-3 UV/IR filter, TPO (Askar) 180mm, F/4.5.

Comet Leonard on Jan 4th, 2022

Comet Leonard on Jan 4, 2022, 00:33 UT (Jan 3, 2022, 6:33 PM CST.) 9×120 sec, Gain 11, Offset 50, QHY183c at -20C, UV/IR filter, Astro-Tech AT60ED at F/4.8.
Comet Leonard on Jan 4, 2022, 00:33 UT (Jan 3, 2022, 6:33 PM CST.) 9×120 sec, Gain 11, Offset 50, QHY183c at -20C, UV/IR filter, Astro-Tech AT60ED at F/4.8. Jet trails intact.

I managed to get some images of Comet Leonard (C/2021 A1) despite it being just under 7 degrees above the horizon at the start of the sequence. Twilight, haze layers, clouds, air traffic, light pollution and atmospheric turbulence were some of the obstacles I had to overcome.  Oh, and huge flocks of geese were flying through the field, too!   lol

Luckily, the comet was not moving much relative to the stars, so the processing was not too difficult. Exposure was 9×120 seconds. I took 24 shots, but many were in strong twilight or had multiple jets crisscrossing over the comet and ruining the view. Some were when the comet was below 4 degrees and the guiding was horrible due to turbulence.

C/2021 A1 (Leonard) on Dec 23, 2021

Dec 23, 2021, 00:26-01:00 UT – Star Streaks version. 33×60 sec, QHY183c at -20C, gain 20, offset 50, UV/IR filter, Astro-Tech AT60ED at F/4.8. Semi-dark location (Bortle 4,) clear and above average transparency.
Dec 23, 2021, 00:26-01:00 UT – Star Freeze version. 33×60 sec, QHY183c at -20C, gain 20, offset 50, UV/IR filter, Astro-Tech AT60ED at F/4.8. Semi-dark location (Bortle 4,) clear and above average transparency.

My, my… what a difference a day makes.
I was hoping Comet Leonard (C/2021 A1) would keep the show going, but it looks like the outburst it had for the past few days is over with, at least for the time being.

After Comet Leonard set, I was interested how another comet nearby would look, so shot 21 minutes worth of subs to take a peek:

Comet 19/P (Borrelly) on Dec 23,2021, 01:15 UT. 21×60 sec, Gain 20, Offset 50, QHY183c at -20C, UV/IR filter, Astro-Tech AT60ED at F/4.8.