The Principle Investigator and collaborators will continue the worlds highest-precision and deepest-reach survey for planets around nearby stars. Extrasolar planets are detected indirectly by measuring the reflex barycentric wobble of a star caused by tugging from its unseen orbiting planet. To date, this is the only method that has succeeded in securely finding extrasolar planets. About 70% of the 100 known planets were discovered by the research team of this project. Their planet survey reaches a precision which allows stellar velocity wobbles as small as 2-3 meters per second to be tracked, revealing planetary companions down to only a few earth-masses in the best cases. The Keck survey, underway since 1996, is monitoring about 700 stars within 150 light-years of the Sun for planets, and is steadily accumulating the large numbers of planets required to characterize planetary systems. This research will also identify the most promising targets for finding earth-like planets around nearby stars, planets that space missions may someday be able to image and probe for evidence of life signs.
Broader Impacts. The Keck exoplanet survey serves as a vehicle for educating young scientists, particularly female astrophysics graduate students. Their participation advances discovery while promoting the teaching and training of woman astronomers, an underrepresented group in astrophysics. Public outreach further broadens the impact. The hunt for extrasolar planets resonates strongly with the public, and has dominated the pages of popular science media for the past 6 years. The proposers give many public talks, press interviews, talks at scientific conferences, and write popular review articles.
