Moon, Jupiter and Mars

My objective for this session was to take advantge of the forecasted average seeing to brush up on my planetary imaging skills.

Setup went without a hitch. I also set up to check collimation with the artificial star, but the air was not still enough before I had to begin cooking dinner at 1800. I set the dew heater on high and came back inside.

I was back out at the scope by 1915. The temperature was around 51 degrees and the RH was 75%. The air was completely still and the metal table was completely dry. I noticed that the moon was down in the tress as Stellarium had projected.

My first task was to check collimation. The artificial star was still quite jumpy, but on average seemed to be more or less centered. I didn’t think that I could improve the collimation, so I moved on to polar alignment.

As I was about to check polar alignment, I noticed the moon peeking through a small gap between two trees, so I decided to attempt a capture. I was unable to acquire it and get focused before it had moved into the next tree.

Next, I checked polar alignment, which I expected to be significantly off as a result of jostling the mount to get the Meade up on it. I would guess it was about a degree off. I adjusted the mount and moved on.

Although I wanted to wait until after 2200 to image Jupiter with the GRS in view, I went ahead and did a preliminary capture of 5 RGB runs at 30s per filter. This preliminary image was processed and posted while I was waiting to go back out for the main Jupiter capture.

I was back inside by 2010. The temperature was 47 degrees when I came in, and there was no dew on the metal table.

The second Jupiter capture was from 2205 to 2225. The temperature was 42 degrees and the RH was 85 percent. There was no dew on the table and the air was still. The image on the display during the capture was consistent with the Average seeing forecast. My main capture with the GRS visible was 10 RGB runs at 30s yielding 2900 frames per filter.

After setting an alarm for 0330, I made it outside for Mars captures at 0345 and was out until 0425. The temperature was 35 degrees and RH was 98%. The air was still and there was dew on the metal table. The front glass was as clear as a bell. The live image on the display looked better than Average. I was well-bundled but started getting chilly by the end. My fingers were getting cold, but I couldn’t operate the handset to manually guide with gloves on.

I made three capture runs in a small ROI: one IR run of 90s, three RGB runs of 60s per filter, and one RGB run of 90s per filter. I’ll look up more frame counts and rates when I process, but I was seeing the FPS bounce around between 400 and 700 when during the R captures. And finally, I made one full FoV run of 30 frames with 1s shutter in L to capture Phobos and Dione.

Unless I discover something else in processing, the only item I have that requires attention is autoguiding in Firecapture so that I do not have to work for extended periods of time with my hands exposed. The remaining captures this year are likely to be as cold or colder. Jupiter and Saturn will have shifted toward the cooler months when they come around again next year. How to connect to the mount requires some thought as both of my laptop USB ports are occupied by the camera and the filter wheel. Two initial ideas come to mind. First, and probably simplest, is to connect to the mount and filter wheel through a USB hub and connect the laptop directly to the camera since the camera requires the highest data throughput. Another idea is to connect the nano-router to the Ethernet port on the mount control panel and connect to it that way.

I discovered a camera rotation issue when I was processing the images. I noticed that the camera alignment had changed when I went out to image Mars. I really didn’t think much of it at the time.

My habit is to align the long axis of the camera frame with the Dec axis of the mount. That way, north and south of the planet (or any object) is at the top or bottom of the frame. Another benefit of this alignment is that during manual guiding, I can recenter the object with just one directional arrow on the hand controller. Having this alignment will be essential to get Firecapture’s auto guiding to function correctly.

When I came out to image Mars, the alignment had rotated about 45 degrees. I was able to quickly figure out which keys to press to recenter, and I moved on. It was too cold to troubleshoot.

But the problem appeared before then. While derotating my 2nd Jupiter image in WINJUPOS, the last image that I captured (at 2200-ish) before shooting Mars, I noticed that the rotation of the wire frame needed to be rotated a just two nudges between any two images. I did not expect much from the final image, but it turned out ok.

It turns out that the issue causing the rotated images was the ASI290 threaded connection to the back of the filter wheel had come loose. The cable and camera stayed in one orientation with respect to the ground, while everything forward of the camera rotated as the telescope tracked the sky. I try to be careful not to overtighten threaded connections as sometimes threads bind up and are difficult to break loose. There’s gotta be a sweet spot somewhere in between.

Now that I have the camera rotation problem solved, I should not have to adjust the wire diagram once it is set properly. It should be good for measuring all of the images in a single run. I didn’t image Saturn last night, but if I had I would have gone 90s per filter, and I would not expect to need to adjust the wire diagram once it is set.

Mars - 2022-10-30 08:00 UTC
Mars (IR)
Jupiter - 2022-10-30 02:18 UTC
Jupiter with Great Red Spot

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