The Henrietta Project

Carnegie Institution Of Washington, Washington DC

Investigators

Abstract

Over the past several decades thousands of planets have been found orbiting stars other than our sun. These are referred to as exoplanets. By studying the atmospheric gas surrounding these exoplanets, insight is obtained into how the planets formed and changed over their lifetimes. To accomplish such a study, this project would build a specialized detector for the 40-inch diameter Swope Telescope in Chile. This detector is sensitive to infrared light which is optimal for measuring the atmospheric gasses of exoplanets. This work is challenging because of the distance and faintness of this signal. Measurement of the large number of exoplanets now known will be important in order to understand the diversity that exists among them. A postdoctoral scholar will lead the design and construction of this detector. The investigators will provide lectures and mentor summer undergraduate internship program at The Carnegie Institution for Science. This project will complete construction of a spectrograph for use on the 40-inch (1-m) Swope telescope at Las Campanas Observatory. This will be accomplished through the procurement and integration of a new infrared detector and controller. Techniques will also be developed that will deliver ultra-precise (100 ppm or better), near-infrared, exoplanet atmospheric spectra from the ground, allowing information on gas giants and sub-Neptunes to be recovered. This instrument will be utilized in an observing campaign to develop the protocols needed to allow such routine high-precision spectrophotometry. Careful design of the instrument and such protocols will mitigate systematic effects such as atmospheric scintillation noise, subpixel sensitivity noise, and scattered light that otherwise limit precision to >350 ppm. Exoplanet atmospheric spectra are imparted with molecular absorption features that permit the measure of atmospheric compositions and pressure-temperature profiles, and unravel the interplay of atmospheres with formation, clouds, oceans, and host star illumination. The PI will be a lecturer in Carnegie's ten-week summer student program over a three year period teaching a total of about thirty under-represented undergraduate students the principles of astronomical instrumentation. 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.