PREDNASAJUCI / LECTURER :

Sergey Shugarov

NAZOV / TITLE :

Photometric study of superoutbursts of WZ Sge-type dwarf nova V627 Pegasi

ABSTRAKT / ABSTRACT :

Cataclysmic variables (CVs) are close binary systems consist of an
accreting primary white dwarf and a secondary low-mass star. Dwarf
novae (DN) are a subclass of CVs which possess an accretion disk
and show recurrent outbursts. The mechanism of DN outbursts is
explained by the thermal instability model in an accretion disk.
DNe of WZ Sge type show a long (several years and even decades)
cyclicity between outburst and their amplitudes up to 8 magnitudes.
We present our UBVRI CCD photometry in 2010 and 2021 of a dwarf nova
V627Peg, discovered in 2010 and classified as a WZ Sge-type star.
The star had 3 outbursts that occurred in 2010, 2014 and 2021.
We have studied the outbursts of 2010 and 2021 in most detail,
using both our own and other published observations. The
similarities and differences in the light curves and color indices
for these outbursts are shown. The change in the periods of
superhumps has been studied and O-C diagrams were plotted for this star.
Changes of the period, amplitude, and brightness during outbursts are
analyzed. Some physical characteristics are calculated, such as the
masses of the components, relative luminosities, outburst and orbital
variations, and the period change rate.