The Mass Dependence of Planet Formation: A Search for Extrasolar Planets Around A-F-type Stars

行星形成的质量依赖性：寻找 A-F 型恒星周围的系外行星

• 批准号: 5453590
• 负责人: Professor Dr. Artie P. Hatzes
• 金额: --
• 依托单位: Thüringer Landessternwarte Tautenburg (TLS) - Karl-Schwarzschild-Observatorium
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5453590?language=en
• 关键词: Mass; Dependence; Planet; Formation; Search

This project will start the first extensive search for extrasolar planets around A-F type main sequence stars using precise stellar radial velocities (RV). These stars have largely been ignored by all current survey. As a result we only have knowledge about extrasolar planets around stars covering the narrow spectral (and thus mass) range of stars F8-K1. Consequently, we have little understanding of how planet formation varies with the most fundamental parameter of a star - its mass. Several programs are searching for planets around late type M-dwarfs, but no systematic search has been made for planets around early- type stars. By finding planets around the more massive earlier type stars we can probe how the process of planet formation depends on the mass of the host star which is of fundamental importantance for planet formation theories. This program will search for extrasolar planets around a special class of A stars, the chemically peculiar Ap stars. These objects are more suitable for RV searches over normal A-stars because they rotate less rapidly and they have peculiar abundances which translates into a high density of spectral absorption lines. Preliminary measurements indicate that a radial velocity precision of about 7 m/s is possible for these stars. Such measurements will be able to detect extrasolar giant planets in orbit around these stars. We propose to search for extrasolar planets around a significantly large sample (at least 100 stars) of A-type stars and thus probe the dependence of planet formation on stellar mass.

该项目将使用精确的恒星径向速度（RV）开始首次广泛搜索 A-F 型主序星周围的太阳系外行星。这些明星在很大程度上被当前的所有调查所忽视。因此，我们只了解恒星周围的太阳系外行星，涵盖恒星 F8-K1 的狭窄光谱（以及质量）范围。因此，我们对行星的形成如何随恒星最基本的参数（其质量）变化知之甚少。有几个项目正在寻找晚期 M 型矮星周围的行星，但尚未对早期型恒星周围的行星进行系统搜索。通过寻找质量更大的早期类型恒星周围的行星，我们可以探究行星形成的过程如何取决于主恒星的质量，这对于行星形成理论至关重要。该计划将寻找围绕一类特殊的 A 型恒星（化学性质奇特的 Ap 型恒星）周围的系外行星。这些天体比普通 A 星更适合 RV 搜索，因为它们旋转速度较慢，并且具有特殊的丰度，可以转化为高密度的光谱吸收线。初步测量表明，这些恒星的径向速度精度可以达到约 7 m/s。这样的测量将能够探测到围绕这些恒星运行的太阳系外巨行星。我们建议在一个相当大的 A 型恒星样本（至少 100 颗恒星）周围寻找太阳系外行星，从而探究行星形成对恒星质量的依赖性。