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

该项目将扩大通过精确RV技术搜索G-K巨星周围的太阳系外行星的调查，该技术于2004年2月在TLS使用2米Alfred Jensch望远镜开始。到目前为止，有超过400颗太阳系外行星围绕太阳以外的其他恒星运行。然而，主星的光谱类型F8-K1涵盖了一个狭窄的质量范围，即恒星的质量接近1 M。因此，我们对行星的形成如何依赖于星星的质量知之甚少，特别是对于中间恒星。早期型恒星是RV搜索的困难目标，因为快速旋转速率使少数线条变宽。另一方面，从MS演化出来的恒星由于温度较低和旋转速度较慢而有大量合适的窄。因此，我们建议将最初的62颗G-K星的Tautenburg样本扩大到300-500颗星。此外，RV测量，我们将确定准确的大气参数，如Teff，g和[Fe/H]为每个星星。这不仅对确定恒星质量的等时线拟合很重要，而且对寻找宿主星星的性质（如[Fe/H]）与太阳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.