Apr 17, 2025 · It receives 1.28 times the light intensity of Earth, and its equilibrium temperature is minus 2 degrees Celsius (28 degrees Fahrenheit). Earlier observations of K2-18b identified methane and …

Jul 20, 2025 · This study explores the parameter space of metallicity, C/O ratio, and Kzz for K2-18 b using the non-equilibrium chemistry model FRECKLL and JWST data. We generated spectra from a …

Sep 27, 2019 · With a bulk density between Earth and Neptune, K2-18b may be expected to possess a H/He envelope. However, the extent of such an envelope and the thermodynamic conditions of the …

Utilizing the Hubble Space Telescope, astronomers have revealed that K2-18b’s atmosphere contains water vapor. Crude models predict that K2-18b’s effective temperature falls somewhere between …

Sep 18, 2025 · An exoplanet orbiting a dwarf star 124 light-years from Earth made headlines around the world in April 2025. Researchers at the University of Cambridge reported that planet K2-18b could be …

Jul 22, 2025 · Although equilibrium models can reproduce the data, physical conditions indicate that the atmosphere is in a non-/ equilibrium state, highlighting the limited constraints from current …

K2-18b has a mass of about 8.6 M⊕, a radius of about 2.6 R⊕, and an orbital period of 32.94 Earth days1 (Montet et al. 2015; Benneke et al. 2019). It has an equilibrium temperature of ∼280 K with …

Nov 23, 2020 · We present simulations of the atmosphere of K2-18 b using Exo-REM, our self-consistent 1D radiative-equilibrium model, using a large grid of atmospheric parameters to infer …

Dec 1, 2025 · This relationship is known as the law of mass action (or law of chemical equilibrium) and can be stated as follows: (3.2.5) K = [C] c [D] d [A] a [B] b where K is the equilibrium constant for the …

With an equilibrium temperature <300 K, the sub-Neptune K2-18 b has spectral features detected at 1.1 – 1.7 microns in transmission, and thus an H2/He-dominated atmosphere amenable for further …