A Search for Extrasolar Planets from the South Pole

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This project will operate a small optical telescope at the South Pole to search for and characterize extrasolar planets, by continuously following a southern Galactic star field with a Charge-Coupled Device photometer, searching for the periodic dimming that occurs as a planet transits its parent star. The recent discovery of many close-in giant exoplanets has expanded our knowledge of other planetary systems and has demonstrated how different such systems can be from the Solar System. However their discovery poses important questions about the effects of such planets on the presence of habitable planets. To date only one extrasolar planet - HD 209458b - has been observed to transit a parent star. This project has the potential for a tenfold increase in the number of extrasolar planets for which transits are observed. The South Pole is an excellent location to detect such planets because of the long winter night, during which randomly-phased transits can most efficiently be detected. Also, the constant altitude of a stellar field at the pole avoids large daily atmospheric extinction variations allowing for higher photometric precision and a search for smaller planets.Specifically, the project will establish an automated planet-finding photometer at the South Pole for two austral winter seasons. Based on the statistics of planetary systems of nearby solar-type stars, about ten to fifteen extrasolar planets should be detected. There is also a possibility of finding lower mass planets that have not previously been detectable. Combining the transit results (which give the size of the planet) with Doppler velocity measurements (which give the planetary mass) will allow determination of the planetary density, thus indicating whether the planet is a gas giant like Jupiter, an ice giant like Uranus, or a rocky planet like the Earth. These data will provide basic observational information that is vital to theoretical models of planetary structure and formation.