Design Study: Mission to Alpha Centauri

在半人马座阿尔法星系统中，一个质量和轨道周期与金星、地球和火星相似的行星系统应该可以被探测到，使用目前2米/秒的多普勒光谱精度，结合极端的节奏，即每晚数百次观测，每个可能的夜晚。这种观测节奏可以达到每秒几厘米的有效精度，已经在星震学项目中得到了证明，这将足以满足这一目的。在这里,Drs。Debra Fischer（旧金山州立大学），R. Paul Butler（华盛顿卡内基研究所）和Gregory Laughlin（加州大学圣克鲁兹分校）将进行一项设计研究，将最近退役的Blanco光谱仪与Cerro Tololo美洲天文台的1.5 m SMARTS联合望远镜进行光纤耦合。这项设计研究将确定开始这样一个长期的、高节奏的多普勒调查的可行性，以寻找我们太阳系中最近的五颗恒星周围的四颗岩石行星的类似物：半人马座α a和B， Ceti Tau， GJ780和Hydri β。这个项目有可能催化地面多普勒测量战略的巨大变化，这将有助于为未来的科学资金和资源分配提供信息。观测还将通过星震学提供关于恒星大气的前所未有的信息，对g0型恒星半人马座阿尔法星A和k0型恒星半人马座阿尔法星b进行差异比较。这项工作由天文科学部恒星天文学和天体物理学项目资助，作为探索性研究的小额资助。

A system of planets with masses and orbital periods similar to Venus, Earth and Mars should be detectable in the Alpha Centauri system using the current spectroscopic Doppler precision of 2 m/s combined with extreme cadence, i.e., hundreds of observations per night, every possible night. This observing cadence could achieve an effective (phase-binned) precision of a few centimeters per second, already demonstrated in asteroseismology programs, which would be sufficient for this purpose.Here, Drs. Debra Fischer (San Francisco State University), R. Paul Butler (Carnegie Institute of Washington), and Gregory Laughlin (University of California - Santa Cruz) will conduct a design study to fiber-couple the recently decommissioned Blanco spectrometer to the 1.5-m SMARTS consortium telescope at the Cerro Tololo Inter-American Observatory. This design study will determine the feasibility of beginning such a long term, high-cadence Doppler survey to search for analogs of the four rocky planets in our solar system around five of the nearest stars: Alpha Centauri A and B, Tau Ceti, GJ780 and Beta Hydri. This program has the potential to catalyze dramatic changes in the strategy for ground-based Doppler surveys that will help inform future allocation of science funding and resources. The observations will also provide unprecedented information about stellar atmospheres via asteroseismology, differentially comparing the G0-type star, Alpha Centauri A, and the K0-type star, Alpha Centauri B. This work is funded from the Stellar Astronomy and Astrophysics program of the Division of Astronomical Sciences, as a Small Grant for Exploratory Research.