Contrary to forecasts the sky’s clear. Even with a 73% illuminated 9 day old waxing moon close to zenith this may be the best opportunity to capture C/2022 E3 at closest approach. The scopes are already set up and calibrated, with the ASI 172 on the 80mm long tube as a guide scope and the ASI 2600MC/P on the 102mm triplet (with Optolong LP-P broadband filter mounted). Hopefully the filter will help combat the moonlight.
Comet C/2022 E3 ZTF With tonight’s Bortle 6 sky and with the filter it’s doubtful that the comet can be captured in individual frames so as to eventually create a GIF, so imaging is initiated with 3-min exposures. Every one of the first 5 frames captures a jet in the TFG landing pattern. So the camera’s dropped down to 1-min exposures. Of a total of 61 1-min frames only 7 are lost to jets.
- prestretched 2.jpg (1.05 MiB) Viewed 514 times
18:26 – 19:27 hrs, 30 Jan 2023
Explore Scientific 102mm triplet refractor with Optolong LP-P filter and ASI 2600MC-P camera
54 X 1 min, unbinned, 200 gain, -20° C cooling, unguided as very close to NCP
The comet’s 60° from the moon so the dome top shutter is partially closed to prevent light from bouncing around inside the scope’s dew shield. The lower dome shutter is also in place to prevent local lights from shining on the scope.
Tonight this fast moving comet’s .3 AU (27 million miles) from Earth and is reportedly very bright. The comet was discovered last March, and ZTF is named after the Zwicky Transient Facility (where it was discovered).
Stacked in Deep Sky Stacker, stretched in ImagesPlus and subsequently processed in PhotoShop.
I’ve not yet been successful in viewing the comet. But setting up behind the scope and using the scope as a pointer a dim star that’s a bit fuzzy is observed. Probably the most disappointing comet sighting I’ve experienced.
The Moon is overwhelming tonight. At 20:08 hrs. seeing is very good. Smile Luna.
- 230130 Luna.jpg (3.09 MiB) Viewed 514 times
Here’s an enlargement:
- Montes Apenninus .jpg (3.52 MiB) Viewed 514 times
Montes Apenninus are a rugged mountain range approximately 600Km long with peaks rising to 5Km high. The crater in the bottom left corner is Eratosthenes which is 58Km across.. They are named after the Apennine Mountains in Italy. With their formation dating back about 3.9 billion years, Montes Apenninus are fairly old.
The transparency is slowly deteriorating but it’s early yet, so the scope is slewed to M81/M82.
- m8182 s.jpg (1.17 MiB) Viewed 514 times
20:31 – 21:34 hrs, 30 Jan 2023
Explore Scientific 102mm triplet refractor with Optolong LP-P filter and ASI 2600MC-P camera
17 X 3 min, unbinned, 200 gain, -20° C cooling, unguided as very close to NCP
Only 17 of 24 frames were usable due to being in the airport flight path. Consequently the S/N is limited, as is post processing. The filter seems to have helped with this one as the transparency is deteriorating and the sky is becoming brighter. Imaging terminated due to loss of transparency.
In at 20:46 hrs. The temperature’s down to 38° F.
Conclusions & lessons learned:
Not bad for a moonlit night.
The comet image was processed a couple of different ways. The best result was to pre-stretch all frames with the IP arcsinh function before moving the frames to AutoStakkert. I’ve been attempting to process it in PIPP and while I’ve generated GIF and AVI annimations they’re very slow and need work.
I do wonder how people achieve those images showing long comet tails?
