Test and Imaging Night Cut Short

I had hoped to do some PEC testing, colour calibration, and trial imaging tonight. The sky cleared around 5PM, on schedule, and was supposed to stay clear until about midnight. Poor transparency, but no moon — it’s ‘way past 3rd quarter, and won’t rise until later.

First, I re-did another test of Periodic Error using PEMPRO, about 6 worm cycles of data. Then calculated a PE correction curve and uploaded it to the mount. With this curve in place I did another test with Periodic Error Correction turned on, and got residual error of ± 1 pixel — about as good as I can hope for, and easily correctable with guiding. Next, I imaged a G2V star in RGB to help calibrate my colour filter exposure times.

By the time I did this the sky was getting quite hazy, so I’m not sure these numbers will be accurate, but they’ll be a start. By the time I finished the G2V captures, the sky had 90% clouded over — at only about 7:30 PM. That was disappointing, only 90 minutes of clear sky and none of it very good. So, I closed down. No images to share tonight. It’s very frustrating weather. At least with the Skyshed POD it’s only a matter of a couple of minutes to start and stop a session, so it’s possible to get some use out of even these short sessions.