报告题目：Astrometry for exoplanet search and SUSI

报 告 人：Yitping Kok(悉尼大学)

摘　  要：Ever since the discovery of the first exoplanet around a main-sequence star, the radial velocity (RV) technique has become the workhorse of exoplanetary detection. The recent discovery of an Earth size planet around a component of the nearest stellar system, α Cen B, at RV of ~0.5m/s demonstrates the exquisite sensitivity this technique can now achieve. Despite this maturity, it is insensitive for detecting planets around intermediate mass (IM) stars which mostly exhibit A/B-type spectra (Galland et al., 2005). Statistics of planets detected around evolved lower-mass IM stars show that these planets have larger minimum masses and semi-major axes as well as a higher occurrence rate of giant planets, 9-27% (Bowler et al., 2010; Johnson et al., 2010; Lovis et al., 2007), compared to Sun-like stars, 6% (Bonavita et al., 2007). This supports the idea that planetary formation is more efficient around higher mass stars (Kennedy & Kenyon, 2008). In order to directly search for planets around IM stars, alternate techniques must be used. Direct imaging, which is fundamentally limited by the large contrast ratio between star and planet, attains its highest sensitivity for hot young planets at distances far (5AU) from their host stars. The best, still under-utilized, method to search for planets, particularly giant ones, within a 20AU radius around IM stars is high precision astrometry. In this talk I will introduce the principle behind the technique and efforts being pursued by the international astronomical community, especially at the Sydney University Stellar Interferometer (SUSI), in this field of research.

时　  间：2012年12月4日（星期二）下午3:00

地　  点：苏富特 三楼 会议室

欢迎参加！

　　　　　　　　　　　　　　　　　　　　　　　　　南京大学天文与空间科学学院