Outputs – Page 2 – Variable stars observer DPV

Flares on red dwarfs

By-product of the Project dwarf are the observation of flares on red dwarf in binary systems. The project dwarf is aimed at detection of circumbinary extrasolar planets using the timing of the minima of low-mass eclipsing binaries. There are many red dwarf stars among the observed objects. Thus time to time some flare was detected. Object GJ3236 turned to be the most active one. Another one was AD Leo, subject of 2019 campaign

Visual observations

Light curves of several semiregular and symbiotic variables from my program. Visual estimates together with data from ASAS-SN survey and CCD observations from AAVSO database. Some time visual data are useful (WY And), sometime the advantage of one visual observer is visible (CH Cyg), sometime visual data fill the gap in the survey data (TZ Cep), sometime visual observation are completely wrong (CK Vir).

V723 Cas

Nova Cas 1995 probably finished its long supersoft X-ray source phase. This SSS phase was accompanied with periodic (0.6932672d) brightness variation interpreted as orbital wave. The amplitude of these variations increased until 2005. It reached 2.0 mag in the B band. Then it was decreasing slowly. The abrupt change came in 2015. Goranskij et al. reported amplitude only 0.3 mag (2015ATel.7985….1G). I observed V723 Cas regularly since 2010 with 1 meter VNT telescope. Unfortunately in 2015 Goranskij was the first to observe the target.

Eclipsing polar V808 Aur

Previously known as CRTS J071126.0+440405 discovered in January 2009 by Catalina Sky Survey as relatively bright polar with deep eclipses. In the active state there is a pre-eclipse dip at phase -0.13 interpreted as eclipse caused by accretion stream falling toward white dwarf. The deep eclipse is the occultation of the hot spot by the secondary. The hot spot is also occulted by the white dwarf itself for half the spin period, opposite to the phase of the deep eclipse. I’m observing the object with 1 meter VNT telescope several times each season. High and low states with 3 magnitude difference are also observed.