Investigation of the Key Parameters in the Process of Extrasolar Planet Formation around Intermediate-Mass G-K Giant Stars

该项目将通过2004年2月在TLS开始的精确RV技术，扩大搜索围绕G-K巨星的太阳系外行星的调查，该技术使用2米阿尔弗雷德·詹施望远镜。迄今为止，有超过400颗系外行星围绕着太阳以外的其他恒星运行。然而，主星的质量范围很窄，被光谱类型F8-K1所覆盖，即恒星的比热比热接近1 M。因此，我们对行星的形成如何取决于恒星的质量知之甚少，特别是对于中间恒星。早期型恒星是RV搜索的困难目标，因为由于快速的旋转速度，很少有线条变宽。另一方面，从MS演化而来的恒星由于温度较低和自转速度较慢而有大量合适的狭窄。因此，我们建议将最初的62颗G-K恒星的陶登堡样本扩大到300-500颗恒星。此外，对于RV的测量，我们将确定每颗恒星的精确大气参数，如Teff、g和[Fe/H]。这不仅对于确定恒星质量的等时拟合很重要，而且对于寻找宿主恒星的性质（例如[Fe/H]）与系外行星的频率和特征之间的任何相关性也很重要。

This project will expand the survey for searching for extrasolar planets around G–K giants via the precise RV technique that was started in February 2004 at TLS using the 2m Alfred Jensch telescope. To date there are more than 400 extrasolar planets in orbit around other stars than our Sun. However, the host stars span a narrow mass range covered by the spectral types F8–K1, i.e. stars having nearly 1 Mסּ. We know therefore little about how planet formation depends on the mass of the star, particularly for intermediate stars. Early-type stars are difficult targets for RV searches due to the few lines that are broadened by rapid rotation rates. On the other hand, stars that have evolved off the MS have a large number of suitable narrow due to cooler temperatures and slower rotation rates. Thus we propose to expand the initial Tautenburg sample of 62 G–K stars to 300–500 stars. Moreover to the RV measurements we will determine accurate atmospheric parameters such as Teff, g und [Fe/H] for each star. These are important not only for isochrone fitting for the determination of the stellar mass, but also to search for any correlations of properties of the host star (e.g. [Fe/H]) with the frequency and characteristics of the extrasolar planets.