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!