New Constraints On DMS and DMDS In The Atmosphere Of K2-18 b From JWST MIRI

The mid-infrared transmission spectrum of K2-18 b obtained with the JWST MIRI LRS instrument. The data points with error bars (in brown) show the observed spectrum as described in section 2.1. The horizontal errorbars correspond to the spectral bin width. The dark blue curve denotes the median retrieved spectral fit, while the two lighter shaded regions denote the 1- and 2-σ intervals. The prominent features of DMDS and DMS are identified. Both molecules have overlapping spectral features between 6.8-8 µm, with broader features between ∼9-10 µm for DMS and ∼10-11 µm for DMDS. The individual spectral contributions of these molecules are shown in Figure 3. -- astro-ph.EP

The sub-Neptune frontier has opened a new window into the rich diversity of planetary environments beyond the solar system. The possibility of hycean worlds, with planet-wide oceans and H2-rich atmospheres, significantly expands and accelerates the search for habitable environments elsewhere. Recent JWST transmission spectroscopy of the candidate hycean world K2-18 b in the near-infrared led … Continue reading New Constraints On DMS and DMDS In The Atmosphere Of K2-18 b From JWST MIRI