SSP seminar

Exploring new parameter space with the Anglo-Australian Telescope

Rob Wittenmyer (UNSW)

Tuesday 13th April 2010, 12:00pm
Pratt conference room, 60 Garden Street

With more than 400 extrasolar planets now known, it is critically important to expand our efforts into new regions of parameter space. I describe three projects now underway which will contribute to a more complete understanding of planet formation by better characterising the population of exoplanets. (1) We are pushing to ever-lower planetary masses with 48-night continuous observing blocks. These "Rocky Planet Search" campaigns have yielded five low-mass planets, including the first super-Earth orbiting a Sun-like star. I also describe an intensive radial-velocity search for Earth-mass planets in the habitable zones of Alpha Centauri. (2) At the Anglo-Australian Telescope, we have begun a survey of Southern evolved, high-mass stars 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 of planets orbiting stars more massive than the Sun. (3) The Anglo-Australian Planet Search (AAPS) has accumulated 12 years of high-precision radial-velocity data. This long time baseline, combined with the excellent long-term stability of the UCLES spectrograph and the adoption of observing strategies which mitigate the impact of stellar oscillation noise, enable us to place meaningful constraints on the frequency of Jupiter analogs. I present preliminary estimates of detection sensitivities from the AAPS main program. Taken together, these three projects push the frontiers of exoplanet parameter space toward lower-mass planets, higher-mass stars, and longer planetary periods, demonstrating that the AAPS is able to effectively probe these exciting new regimes.


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