双星与变星研究组知识库

HW Vir-like eclipsing binaries are a group of detached binary systems that consists a very hot subdwarf B (sdB) type primary and a fully convective M-type secondary with short period. They display very narrow eclipse profiles, which give highly precise eclipse times. By analyzing the constructed observed-calculated (O-C) diagram based on the sdB eclipsing timings, We found very small-amplitude orbital period variations due to the presence of potential substellar object tertiaries (exoplanets and brown dwarfs) can be detected. The discovery of circumbinary substellar objects orbiting HW Vir-likeeclipsing binaries has very important implications for the formation of sdB stars and the fates of low-mass companion systems, etc. A search for the substellar objects around the HW Vir-like Binaries is one of the projects of our research group of Yunnan Observatories (YNO), which has been started from 2006. In this paper, we will present some new results on our three targets of this project, i.e. NSVS14256825, HS0705+6700 and NSVS07826147.