A Deep Search for Transiting Extrasolar Planets

Carnegie Institution Of Washington, Washington DC

Investigators

Abstract

AST-0206278 PI Seager Planets orbiting other stars are too faint to be observed directly with current technology, but it is possible to detect them indirectly by observing their parent stars. Close to 80extrasolar planets are currently known, all of them detected via the "radial velocity "technique. These extrasolar planets are not seen directly, and thus even their most basic physical characteristics, such as radius and actual mass, cannot be measured. This project will carry out a planet transit search, an alternative and complementary approach to the radial velocity technique. The planet transit search method involves looking for the tiny drop in brightness of a star caused by a planet as it periodically passes directly in front of its parent star (i.e. transits). While most stars with planets will not show transits, stars with planets in short-period ( ?4 days)orbits are most likely to show transits. Considering the known population of short-period planets, approximately 1 in 10,000 stars will have a short-period planet that shows transits in 10 to 15 nights of observations. Looking at 10,000 stars one-by-one is far too time-consuming to be feasible. Instead the transit search method involves monitoring tens of thousands of stars simultaneously. Specifically, the PI will search for a periodic 1%drop in brightness every time the planet passes in front of the parent star. A successful planet transit search will have a huge impact on the field of extrasolar planets because every planet detected will have a measured radius providing a constraint on evolutionary and atmosphere models for these planets.