Design Study: Mission to Alpha Centauri

San Francisco State University, San Francisco CA

Investigators

Abstract

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.