CRAQExploring exoplanet atmospheres with the JWST MANATEE program
Thomas Green
NASA Ames
The JWST MANATEE MIRI and NIRCam guaranteed time program has observed panchromatic near-to-mid-infrared transmission and emission spectra of nine transiting exoplanets ranging in mass from 1.4 ? 360 Earth masses and equilibrium temperatures of 400 ? 1200 K. I will recap our initial results including the discovery that the rocky planet TRAPPIST-1 b lacks a substantial atmosphere, the first detection of CH4 in the transmission and emission spectra of a transiting planet (WASP-80 b), detection of differences in the evening and morning limbs of WASP-107 b, spatial inhomogeneities in the dayside emission of the warm Saturn WASP-69 b, and detection of H2O, CH4, CO, CO2, SO2, and NH3 molecules in a range of planets with mini-Neptune to Saturn masses. Using model grids and atmospheric retrievals, we have leveraged panchromatic 2.4 ? 12+ micron JWST data and transit/eclipse geometries to constrain the atmospheric compositions, metallicities, C/O ratios, disequilibrium chemistry, atmospheric structures, internal temperatures, effective temperatures, photochemistry, albedos, and cloud/haze properties of these planets. I will discuss how these properties offer insights into dominant atmospheric processes, frequent CH4 depletion, and potential formation pathways of these systems. Some lessons learned regarding coherently analyzing data from multiple observations acquired with different instrument modes at different times will also be presented.
Date: Tuesday, 16 July 2024 Time: 15:00 Where: Université de Montréal Université de Montréal