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Abstracts (2/21) The Age of Exometeorology: Observing the Atmospheres of Transiting Exoplanets -Seth Redfield, University of Texas at Austin High signal-to-noise ratio (S/N) and high spectral resolution observations of transiting exoplanets provide an opportunity to measure the properties of exoplanet atmospheres and exospheres through transmission spectroscopy. I present the results of a large-scale program which led to the first ground-based detection of absorption due to an exoplanetary atmosphere. Observations were taken with the Hobby-Eberly Telescope (HET), which is well suited for this type of program given its large mirror, high resolution spectrograph, and queue scheduling. We observe significant additional absorption in the cores of the neutral sodium doublet relative to the continuum, when in-transit observations are compared to out-of-transit observations. Two tests are performed to confirm the detection: (1) analysis of a strong control line that is predicted to show no absorption, and (2) an empirical Monte Carlo analysis to quantify the impact of systematic errors. Physical properties of the exoplanet atmosphere, such as atomic and molecular composition, cloud altitudes, and wind speeds may be derived from the transmission spectrum. I will discuss the richness of the acquired datasets and describe several complimentary research projects. Observations of several other bright transiting systems are ongoing with the HET, while future large telescopes will push research toward observations of smaller atmospheres (e.g., terrestrial exoplanets), weaker spectral features (e.g., biomarkers), and temporal variability (e.g., weather). A growing sample of transiting exoplanets coupled with continued observational achievements and capabilities are just beginning to make direct comparisons of physical characteristics of exoplanet atmospheres possible, eventually leading to comparative exometeorology. |
28 May 2008
Astronomy Program · The University of Texas at Austin · Austin, Texas 78712
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Astronomy Program · The University of Texas at Austin · Austin, Texas 78712
prospective student inquiries: studentinfo@astro.as.utexas.edu
site comments: www@www.as.utexas.edu