双星与变星研究组知识库

By using 78 newly determined timings of light minima together with those collected from the literature, we analysed the changes in the observed minus calculated (O-C) diagram in HS 0705+6700, a short-period (2.3 h) eclipsing binary that consists of a very hot subdwarf B-type (sdB) star and a very cool fully convective red dwarf. We confirmed the cyclic variation in the O-C and refined the parameters of the circumbinary brown dwarf (reported to orbit the binary system in 2009) by analysing the changes for the light travel time effect that arises from the gravitational influence of the third body. Our results indicate the lower mass limit of the third body to be M-3 sin i(') = 33.7(+/- 1.6) M-Jup. This companion would be a brown dwarf if its orbital inclination is larger than 27 degrees.7 and it is orbiting the central eclipsing binary with an eccentricity e similar to 0.2 at a separation of about 3.7(+/- 0.1) au.