JWST Thermal Emission Spectroscopy of the Super-Earth 55 Cnc e

JWST enables the measurements of the thermal emission spectra of small exoplanets to characterize their atmospheres and surfaces. Such measurements open up a new way to test models of atmospheric evolution and retention. I will present JWST thermal emission observations of a potentially rocky exoplanet, the planet 55 Cnc e, covering the wavelength range between 4 and 12 microns through two eclipse observations using the NIRCam/F444W and MIRI/LRS modes. Prior observations with Spitzer photometry showed that the planet must have either a volatile-rich atmosphere, or a molten lava surface shrouded by a mineral atmosphere while rotating at an asynchronous rate. The JWST observations have the sensitivity to distinguish the volatile-rich atmosphere scenarios versus the mineral atmosphere scenario via spectral features of H2O, CO, CO2, SO2, and SiO, providing one of the first direct detections of a non-H2-dominated atmosphere on an exoplanet. I will also discuss the challenges and mitigations for observing very bright stars using JWST.