exo-Neptune Archives

The ATREIDES Program In Search Of Lost Exo-Neptunes

by Keith CowingSeptember 17, 2025September 17, 2025

An international team led by the University of Geneva (UNIGE), including scientists from the National Centre of Competence in Research PlanetS, the University of Warwick, and the Canary Islands Institute […]

Retrieved spectral feature amplitude, AH, compared to clear, cloudy, and hazy atmosphere models from Morley et al. (2015). For the clear and cloudy models, the dotted lines indicate a 100× Solar metallicity atmosphere, and the dot-dashed lines a 300× Solar atmosphere. All hazy models were calculated at 50× Solar metallicity, the dotted lines are 1% haze precursor conversion, and the dashed lines are 10%. The green open markers, shown for context, are the measured CH4-retrieved AH values for K2-18 b and TOI-270 d. The black open markers, shown for context, are the Kepler-51 planets, which are excluded from the trend analysis due to their exceptionally low densities, and GJ 1214 b, which was found to significantly bias the trend fit due to the extremely precise flatness of its spectrum. -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report

Clouds and Clarity: Revisiting Atmospheric Feature Trends in Neptune-size Exoplanets

by Keith CowingOctober 13, 2023October 13, 2023

Over the last decade, precise exoplanet transmission spectroscopy has revealed the atmospheres of dozens of exoplanets, driven largely by observatories like the Hubble Space Telescope.