The Mt John University Observatory Search For Earth-mass Planets In The Habitable Zone Of Alpha Centauri

Abstract

The "holy grail" in planet hunting is the detection of an Earth-analog: a planet with similar mass as the Earth and an orbit inside the habitable zone. If we can find such an Earth-analog around one of the stars in the immediate solar neighborhood, we could potentially even study it in such great detail to address the question of its potential habitability. Several groups have focused their planet detection efforts on the nearest stars. Our team is currently performing an intensive observing campaign on the alpha Centauri system using the Hercules spectrograph at the 1-m McLellan telescope at Mt John University Observatory (MJUO) in New Zealand. The goal of our project is to obtain such a large number of radial velocity measurements with sufficiently high temporal sampling to become sensitive to signals of Earth-mass planets in the habitable zones of the two stars in this binary system. Over the past years, we have collected more than 45,000 spectra for both stars combined. These data are currently processed by an advanced version of our radial velocity reduction pipeline, which eliminates the effect of spectral cross-contamination. Here we present simulations of the expected detection sensitivity to low-mass planets in the habitable zone by the Hercules program for various noise levels. We also discuss our expected sensitivity to the purported Earth-mass planet in an 3.24-d orbit announced by Dumusque et al.~(2012).

16 pages, 7 figures, accepted for publication in the International Journal of Astrobiology

References in corpus (8)

• Kepler-62: A five-planet system with planets of 1.4 and 1.6 Earth radii in the Habitable Zone
• Terrestrial Planet Formation Surrounding Close Binary Stars
• Planet formation in Alpha Centauri A revisited: not so accretion-friendly after all
• Formation and Detectability of Terrestrial Planets Around Alpha Centauri B
• The Alpha Centauri Binary System: Atmospheric Parameters and Element Abundances
• Planet formation in the habitable zone of alpha Centauri B
• Are Proxima and Alpha Centauri Gravitationally Bound?
• Toward detection of terrestrial planets in the habitable zone of our closest neighbor: Proxima Centauri

Cited by in corpus (6)

• Planet Detectability in the Alpha Centauri System
• Lidov-Kozai stability regions in the alpha Centauri system
• Exomoons in Systems with a Strong Perturber: Applications to $\alpha$ Cen AB
• Evolution of $\alpha$ Centauri B's protoplanetary disc
• HD 83443c: A highly eccentric giant planet on a 22-year orbit
• Effects of Proxima Centauri on Planet Formation in Alpha Centauri