Analysis of TESS observations of V844 Her during the 2020 superoutburst

Abstract

I analyzed Transiting Exoplanet Survey Satellite (TESS) observations of the 2020 superoutburst of the SU~UMa-type dwarf nova V844 Her. This object showed "textbook" superhump stages A, B and C confirmed by modern satellite observations. The resultant figure can be used for an illustration of the concept of superhump stages under the Creative Commons (CC-BY-NC) licence. During the growing phase of superhumps, the period was initially close to, but slightly longer than the orbital period. Observers should pay attention to the presence of such a phenomenon not to confuse the phenomenon with early superhumps seen in WZ Sge stars. After the superoutburst, superhumps were detected for additional 18 d with the same period and no orbital signal was detected. Small wiggles with a period of ~0.5 d were recorded in the post-superoutburst phase and they may be the same phenomenon recorded in the Kepler data of the SU UMa star V585 Lyr.