Abstract
The VRC light curves were regularly measured for the eclipsing binary NSVS 7453183 as a part of our long-term observational project for studying of low-mass eclipsing binaries with a short orbital period and surface activity. The TESS light curve solution in phoebe results to the detached configuration, where the temperature of primary component was adopted to T-1 = 4300K according to the SED approximation.
It gives us T-2 = 4080 +/- 100K for the secondary component. The spectral type of the primary component was estimated to be K6, and the photometric mass ratio was derived q = 0.86.
We confirm presence of the third body in this system, a stellar companion with a minimal mass 0.33M(circle dot) orbiting the eclipsing pair with a short period about 425 days, and propose the next, fourth body with a longer orbiting period of about 12 years, probably a brown dwarf with the minimal mass of 50M(Jup). The hierarchical structure ((1+1)+1) + 1 of this quadruple system is assumed.
Characteristics and temporal variations of the dark region on the surface of the primary component were estimated. The average migration speed of about 10 degrees per month was found during years 2020-2022.