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Category: Jupiter
I haven’t been able to do any planetary imaging for over a year, but was finally able to get to Jupiter this week. Two animations follow.
I’ve also included a several-second snippet from one of the raw video sequences to illustrate the seeing conditions.
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A 45-minute time-lapse animation of Jupiter on November 23, 2023. The Great Red Spot is just about to rotate out of view. |
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A 38-minute animation picking up with the last frame of the animation above. In this animation, the Great Red Spot rotates out of view, and a disturbed region of the North Equatorial Belt transits Jupiter’s central meridian. |
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The seeing during this session was poor to fair with some improvement toward the end. This is a several-second snippet of one of the video sequences captured during the session. This was the view at the telescope and shows a wobbly undulating Jupiter with large scale features visible, but no fine details even for brief intervals. See Damian Peach’s “A Modern Scale of Astronomical Seeing for Imagers.“ |
Observing Details:
November 23, 2023
Animation 1: 01:16:23-02:00:29 UT
Animation 2: 02:00:29-02:38:15 UT
Seeing: Poor-Fair
Transparency: Good
Location: Edmond, Oklahoma USA
Image Details:
Animation 1 consists of 14 images. Animation 2 consists of 12 images. Each image is a stack of the best 3000 of 10000 frames.
Each frame 10.07 ms ; Gain 295
Equipment:
Telescope: Celestron C8 (203 mm f/10) operating at f/20 with 2X Barlow lens
Camera: ZWO ASI224MC with UV/IR cut filter
Mount: Meade LXD75 (under renovation)
Capture:
FireCapture
Processing:
Autostakkert3
Registax
GIMP
This is the last batch of Jupiter images from an August session processed into a single animated GIF. Finally done. This 74-minute animation features Jupiter’s Great Red Spot with a brief appearance of moon Io. Full details of the animated image follow below.
As noted in my previous post here, I have started adding a spacer to my Barlow lens. The rule of thumb for planetary imaging is that the f-ratio of the imaging system should be 5x the the camera’s pixel size in microns. My ZWO ASI 224MC camera has 3.75 micron pixels so the optimum f-ratio is 3.75 x 5 = 18.75. I had noticed that using a 2x Barlow lens, the resulting f-ratio with my f/10 telescope was not f/20, but slightly less at f/18. This is likely caused by the flip mirror system placed in the optical train. By adding the spacer, I increased the distance between the lens component of the Barlow and the camera sensor chip, thereby increasing the system focal length slightly and raising the f-ratio to f/22-f/23. Better to be a little bit over than a little under.
Animation Details:
August 15, 2022 09:21:24-10:34:54 UT
74-minute time-lapse
North is up
Seeing: Good
Celestron C8 (203mm SCT f/10) + Orion 2x Shorty Barlow + 12.7mm spacer (f/22)
ZWO ASI224MC with IR Cut Filter
26 image animation sequence. Each image is stack of best 3000/10000 frames.
Captured with FireCapture
Processed with AutoStakkert3!, Registax, GIMP
I’m still finishing up processing images from imaging sessions in August. Here’s a Jupiter animation captured on August 14th. Full details below.
For this session, I added a 0.5-inch (12.7 mm) spacer between the Barlow lens and the imaging sensor. This added a bit of extra focal length to the scope-camera system and raised the f-ratio from its usual f/18-19 to f/23. Adding the spacer this way effectively converted the Barlow Lens from 2x to 2.5x. Fortunately the seeing was good enough to handle the increase. The picture below shows the configuration.
Animation Details:
August 14, 2022 09:11:24-10:32:04 UT
81-minute time-lapse
North is up
Seeing: Fair-Good
Celestron C8 (203mm SCT f/10) + Orion 2x Shorty Barlow + 12.7mm spacer (f/23)
ZWO ASI224MC with IR Cut Filter
29 image animation sequence. Each image is stack of best 3000/10000 frames
FPS (avg) 63, 15.83 ms, gain 240, ROI 680×348, histogram 58%