I had three objectives tonight, but wasn’t sure that I would hold out through the third. My plan was to capture the moon right after sunset, and go back out after dinner to polar align, and attempt a G11 baselining run for my second objective. My third objective was to see what settings I needed to shoot a star field with the ASI290.

The temperature was about 38 degrees when I went out to shoot the moon at 1745, and it was 30 degrees when I shut down at about 2110. I did not anticipate a dew or frost problem, so I didn’t even turn on the dew heaters. The wind had calmed down before I started. Shooting the moon at about 1200mm focal length, I could not detect a seeing problem. The 1st Quarter moon was did not create any difficulty for my purposes.

This was my second night out as I have resumed work at the telescope in earnest this year. I still had a little bit of rust to knock off, but was able to accomplish the basics without much difficulty.

For the moon, I shot a three panel mosaic with the ASI178MC with the 2.5x PM in the optical path. Each panel was 500 frames, and the histogram was about 70%. I failed to remember or write down the gain and exposure. I plan to apply the mineral moon processing technique.

For the baselining attempt, I was able to get PHD2 up and running, equipment connected, and get and step into a calibration without difficulty. Additionally, I used Stellarium to slew the scope to the meridian. I could not get a good calibration result. Orthogonality was way off, and the graph was an incoherent mess . Guiding was horrible. I saw RMSs that quickly ran up to 25 and 30 or more before guiding failed. I suspected polar alignment and worked on that. I double checked the alignment scope, ran polemaster again, and was happy with that. I tried the Guiding Assistant and it was reading a polar alignment error of 34’.

It seems to me that the real issue is the whatever is causing the calibration problem. Whatever that problem is, it could be preventing the Guiding Assistant Tool from properly reading the polar alignment error. If I get another clear sky opportunity, before I can work on the mount, I will try doing a PHD drift alignment to see if that helps. Otherwise, if I get a chance to work on the mount, I’ll go ahead and do the worm block alignment, install the spring washers and adjust the backlash.

I did most of the baseline work remotely from the inside, but I was out a good bit working on polar alignment. Because I was tired of being cold, I did not attempt the star field imaging with the ASI290. I’ll defer that to another night.

Moon - 2022-02-08 22:42 UTC
The Moon

Leave a Reply