A photometric study of a new short period eclipsing sdB binary NSVS 07826147

Abstract

NSVS 07826147 and NSVS 04818255 were suspected as possible eclipsing sdB binary systems by Kelley and Shaw. In order to investigate the short period eclipsing sdB binaries, we have listed them as our observing targets and began to monitor it from March 2009. Till now, we have obtained four complete CCD light curves and 16 high precise times of light minimum of NSVS 07826147. All light curves show strong reflection and a very narrow eclipse, which implies that NSVS 07826147 should be a new short period eclipsing sdB binary. For the system NSVS 04818255, no eclipse character was found in the light curves according to our observations. However, we found that a star near NSVS 04818255 is a close binary system with a period of about 0.32498 days. Up to now, only seven short period eclipsing sdB binary systems have been found, including NSVS 07826147. With the new precise epochs obtained by us, the new period of this system is derived as 0.16177046(5) days, which can be used to predict the epochs of light minimum. Furthermore, the light curves of NSVS 07826147 are analyzed using the Wilson-Van Hamme code and the testing photometric solutions are presented and discussed.