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ExoPlanet Atmospheres

Addressing the challenges in understanding the nature of Exoplanet Atmospheres from their Spectra

Event Type
Department of Astronomy
134 Astronomy Building
wifi event
Feb 27, 2024   3:45 - 4:45 pm  
Luis Welbanks
Daniel Franco

The 2020s and beyond will be the era of spectroscopy of exoplanet atmospheres. In just 3 years, our field has made dramatic advancements, moving from having very limited wavelength coverage and precision data from the Hubble Space Telescope (HST), to having high-precision spectroscopy over a wide wavelength range (~0.4 to 20μm) with the James Webb Space Telescope (JWST). These exquisite observations come with the opportunity to perform detailed reconnaissance of exoplanet atmospheres, explore their chemical and physical properties, and perform population-level studies to test our hypotheses for planet formation and planetary processes. Thanks to these advancements we could very well be the first generation in human history to answer whether we are alone in the universe.

However, any interpretation is only as good as our understanding of the limits of the data and the model assumptions themselves, a point often overlooked. Whether exploring hot gas giants or temperate terrestrial exoplanets, the future of the field depends on our models' ability to interpret atmospheric properties from observed spectra. This new era in exoplanetary sciences invites us to overcome previous artificial boundaries between observers and theorist and merging both disciplines to fully exploit this wealth of data. In this talk, I will present my efforts to deliver a holistic view of exoplanet atmospheres, answering not only what exoplanet atmospheres are made of, but also which data drive our inferences, how reliable these inferences are, and their place within the larger astronomical context. I will present several early ground-breaking results from observations with JWST. From these observations we detect and constrain several chemical species that were previously elusive, including methane (CH4), ammonia (NH3), sulfur dioxide (SO2), carbon monoxide (CO), and carbon dioxide (CO2), alongside several precise water (H2O) measurements. I will discuss the challenges we are currently facing, and the advancements required for inferring the complete chemical inventory of our diverse exoplanet sample. Our findings underscore the transformative power of JWST and pave the way for future, in-depth atmospheric investigations of a larger exoplanet population.

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