Search for extrasolar planets in binary systems

Abstract

We are searching for extrasolar planets in visual binary systems to understand the planet formation in binary systems or multiple stellar systems by precise Doppler shift measurements, using HIgh Dispersion Echelle Spectrograph(HIDES) equipped on the Okayama Astrophysical Observatory's(OAO) 188cm telescope. Since 2003, we have monitored radial velocity variations about 10 pairs of binary systems every 1 or 2 months. 3 objects show large radial velocity variations as we reported in the last autumn meeting. We here discuss on a cause of radial velocity variation based on data obtained in these 2 years.