Discovery and study of the eclipsing variable star Grigoriev 1

Abstract

This work is dedicated to the discovery of the eclipsing variable star Grigoriev 1 and determining the parameters of its binary system. The star was found through the systematic checking of ultraviolet sources of GALEX space observatory in Pegasus constellation. Analysis of the ZTF project data has shown the presence of eclipses with two magnitudes depth and a period of 6.5997 days. The duration of eclipse covers only 1% of the orbital period, and the partial phases are at least 30 times shorter. Those parameters imply that the star is a detached binary system with a white dwarf seen edge-on. The new object was added to the International Variable Star Index AAVSO VSX as Grigoriev 1. Over the 10 million objects in VSX database there are only 188 variable stars of EA/WD type. Grigoriev 1 has the longest orbital period out of those. Moreover, its absolute magnitude M at maximum light from Gaia space observatory data is about +6.8. On the color-luminosity diagram it occupies the intermediate position between hot subdwarfs and white dwarfs which makes it even more interesting and worth studying at professional telescopes.