[vsnet-alert 10504] OT_J020025.4+441019: superhumps evolution

[Denis Denisenko]

Dear all,

According to CCD observations by S. Korotkiy and T. Kryachko with 80-mm refractor on Caucasus, it looks like the early superhumps have subsided in the last night.  Compare it with the report from a night before.

Sep. 02 observations

Using the data obtained in the last night with 80ED refractor and CCD (fifty 300-sec exposures from Sep. 2.732-2.909 UT), we have improved the period value of the new variable in Andromeda.  Applying Lafler-Kinman algorithm to the set of 76 data points from Sep. 1.843 to 2.909 UT we find a period of 0.0563(1)d.  The full amplitude of variation remained at 0.13m level, just like on the first night.  Light curve is now clearly showing a double-humped shape.

Periodogram: http://hea.iki.rssi.ru/~denis/VarAnd08-Sep01-02.gif

Sep. 03 observations

There were 216 images with 120-sec exposure taken during Sep. 3.733 and 4.065 UT.  The period search using two different algorithms does not show strong periodic variations in the 0.04-0.1d interval.  Instead, during the 8-hour long run the star appears to be raising by 0.1m first, then fading by 0.15m with the fast fluctuations superimposed.

Periodogram: http://hea.iki.rssi.ru/~denis/VarAnd08-Sep03.gif

Denis