A photometric study of NSVS 7453183: a probable quadruple system with long-term surface activity

• Published in: Monthly notices of the Royal Astronomical Society 2023-01, Vol.520 (1), p.353-363
• Main Authors: Šmelcer, L, Wolf, M, Kučáková, H, Zasche, P, Kára, J, Hornoch, K, Zejda, M, Auer, R F
• Format: Article
• Language: English
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stad053

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 T1  = 4300 K according to the SED approximation. It gives us T2 = 4080 ± 100 K 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 0.33 M⊙ 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 50 MJup. 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° per month was found during years 2020–2022.