CAREER: Precise Ground-Based Spectrophotometry as a Lens for Planetary and Stellar Physics

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

When light passes through a planet’s atmosphere, it meets atoms and molecules that can absorb or scatter it. Astronomers use this fact to learn about the composition and structure of the atmospheres of extrasolar planets (“exoplanets”). When an exoplanet passes in front of its star, as seen from the Earth, a tiny (yet measurable) amount of light is absorbed. Different elements absorb different colors (wavelengths) of light differently. The investigator will use telescopes to study the way exoplanets’ atmospheres absorb or transmit light at different wavelengths. He will then infer the composition and structure of the planets’ atmospheres. This will expand our knowledge of planetary atmospheres beyond those of the eight Solar System planets and give a better idea of how atmospheres form and change with time. The understanding derived will help us better understand how our own Solar System may have arrived at its current state, and how planetary atmospheres, including Earth’s, may change in the future. The investigator will involve a postdoc and undergraduate students in his work. He will also develop a program integrating art and science in a first-year seminar and in an upper-level class on advanced scientific visualization. Finally, he will develop a K-12 program in collaboration with a planetarium and the Colorado Studio for the Arts. The investigator proposes to use his institutional access time to the 3.5-meter telescope at the Apache Point Observatory, in addition to applying for time at Cerro Tololo Interamerican Observatory and the Gemini Observatory. He will address two primary questions: "How do planets accrete and retain their volatiles?" and "How do aerosols form in planetary atmospheres?" He will create an open-source Python package that will enable users to 1) extract time-series spectra from raw data, 2) reduce differential spectrophotometry data, and 3) visualize and fit data sets. The work will also account for noise introduced into exoplanet transmission spectra by starspots. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.