Abstract
I give an update on three major exoplanetary science initiatives being pursued by Australian-based planet-search teams. In addition to the long-running Anglo-Australian Planet Search, I describe the Pan-Pacific Planet Search, a radial-velocity survey of Southern hemisphere evolved, intermediate-mass stars using the 3.9m Anglo-Australian Telescope. We currently achieve velocity precisions of 3-6 m/s, and there are several planet candidates emerging as more data are obtained. In collaboration with John Johnson's Lick and Keck survey of Northern subgiants, this all-sky survey of over 600 stars will significantly improve our knowledge of the frequency and properties of planets orbiting stars more massive than the Sun.
At New Zealand's Mt John Observatory, we are undertaking an intensive observational campaign targeting the nearest Sun-like stars, Alpha Centauri A and B, to search for Earth-like planets in their habitable zones. We are observing year-round for 4 years, with the aim of gathering 50,000 precision radial velocity measurements. This project is the first ultra-deep reconnaissance of nearby Sun-like stars, which is necessary to understand the frequency and characteristics of rocky planets in potentially habitable orbits.
Finally, I present results from our recent series of papers in which we have performed extensive suites of dynamical simulations to test the veracity of proposed multiple-planet systems. We show that some systems are strongly constrained by protected low-order resonances, while others are wildly unstable on short timescales. This work highlights the critical need to include dynamical stability analysis as an integral part of the discovery process for candidate multi-planet systems.
Coffee and tea will be served 20 minutes prior to the seminar.