ASTR 106 observation summary, 19 October 2021, DMW

We got clear skies, and good data, though we missed the beginning of the transit as the sun was still up and the target star hadn't risen yet. We also got high winds -- 10 mph on the average, with gusts to 40 mph, mostly from the west -- and a full moon. The moon was only 35 degrees away from our target, so the background was pretty bright. On the other hand the target was in the east, so we the telescope was shielded well from the wind by the dome. Only very strong gusts caused brief loss of autoguiding, and the image quality (2.4 arcsec seeing) was better than on our first night. 

In all, we took 23 five-minute exposures. After the first two, during which the autoguider was having trouble locking onto the guide star, we switched to a brighter one. This moved the target away from the center of the image, almost all the eastern edge. But observations went very smoothly for the last 21 images, which were taken essentially continuously. Only those last 21 were used in the official version of the light curve.

The result features the transit minimum, transit egress, and post-transit baseline. It can be accurately shifted and combined with our first light curve as the first step of orbital period determination. 

The average of the last 21 frames has some interesting flaws produced by movement during the observations of some of the dust specks on the CCD sensor's window, visible because of the large moonlight background.