I'm continuing to investigate my new monochrome CMOS camera, ASI183MM-Pro, making test observations. Now it was a HADS star KP Lyn. The light curve was obtained with the mentioned camera, a photometric V-filter from Baader Planetarium, and a 150mm Newtonian telescope. The night was clear, however, with almost full Moon.
The data looks quite satisfactory.
I tried to compare my data with KP Lyn observations available via the AAVSO International Database; it turned out that the period and the epoch of maxima from the International Variable Star Index (VSX), in turn, originated from the GCVS, are not accurate enough. Double-checking the star's parameters with ASAS-SN data proved this: a phase plot with VSX period was very fuzzy. So I made a precise determination of times of maxima available in the AAVSO International Database (from December 2008 to present) using an approach previously used in my recent paper "Refining Ephemeris and Estimating Period Change Rate for V965 Cephei" ( https://app.aavso.org/jaavso/article/3707/ ) and built an O-C diagram to check if the period constant. It appeared to be constant with very good stability (data from one observer were definitely discrepant, so I removed them). I determined improved values of the period and the epoch; the corresponding phase plot with ASAS-SN and my data is shown in the attached figure. Thinking about sending a revision to the VSX...
The variable, a comparison, and a check star:
