Results 61 to 70 of about 517 (155)
Bistability, Oscillations, and Multistability on Hycean Planets
The Astrophysical JournalHycean planets are hypothetical exoplanets characterized by H _2 O oceans and H _2 -rich atmospheres. These planets are high-priority targets for biosignature searches, as they combine abundant surface liquid water with easy-to-characterize H _2 -rich ...
Yichen Gao, Daniel D. B. Koll, Feng Ding
doaj +1 more source
The Planetary Science JournalNew observational facilities are beginning to enable insights into the three-dimensional (3D) nature of exoplanets. Transmission spectroscopy is the most widely used method for characterizing transiting temperate exoplanet atmospheres, but because it ...
Nicholas Scarsdale +2 more
doaj +1 more source
Blowin’ in the Nonisothermal Wind: Core-powered Mass Loss with Hydrodynamic Radiative Transfer
The Astrophysical JournalThe mass loss rates of planets undergoing core-powered escape are usually modeled using an isothermal Parker-type wind at the equilibrium temperature, T _eq .
William Misener +3 more
doaj +1 more source
The Radius Cliff is a Waterfall: Explaining Sub-Neptune Exoplanets with Steam Worlds
The Astrophysical JournalThe demographics of Kepler planets provide a key testbed for models of planet formation and evolution, particularly for explaining the radius valley separating super-Earths and sub-Neptunes.
Aritra Chakrabarty +3 more
doaj +1 more source
Irradiated Atmospheres. IV. Effect of Mixing Heat Flux on Chemistry
The Astrophysical JournalVertical mixing disrupts the thermochemical equilibrium and introduces additional heat flux that alters exoplanetary atmospheric temperatures. We investigate how this mixing-induced heat flux affects atmospheric chemistry.
Zhen-Tai Zhang +7 more
doaj +1 more source
A Multispecies Atmospheric Escape Model with Excited Hydrogen and Helium: Application to HD209458b
The Astrophysical JournalAtmospheric escape shapes exoplanet evolution and star–planet interactions, with He I 10830 Å absorption serving as a key tracer of mass loss in hot gas giants.
Anna Ruth Taylor +6 more
doaj +1 more source
Distinguishing Oceans of Water from Magma on Mini-Neptune K2-18b
The Astrophysical Journal LettersMildly irradiated mini-Neptunes have densities potentially consistent with them hosting substantial liquid-water oceans (“Hycean” planets). The presence of CO _2 and simultaneous absence of ammonia (NH _3 ) in their atmospheres has been proposed as a ...
Oliver Shorttle +4 more
doaj +1 more source
The Astrophysical JournalPlanet formation models suggest that the small exoplanets that migrate from beyond the snowline of the protoplanetary disk likely contain water-ice-rich cores (∼50% by mass), also known as water worlds.
Aritra Chakrabarty, Gijs D. Mulders
doaj +1 more source
Precise Constraints on the Energy Budget of WASP-121 b from Its JWST NIRISS/SOSS Phase Curve
The Astronomical JournalUltra-hot Jupiters exhibit day-to-night temperature contrasts upwards of 1000 K due to competing effects of strong winds, short radiative timescales, magnetic drag, and H _2 dissociation/recombination. Spectroscopic phase curves provide critical insights
Jared Splinter +22 more
doaj +1 more source
The Astrophysical JournalConvective processes are crucial in shaping exoplanetary atmospheres but are computationally expensive to simulate directly. A novel technique of simulating moist convection on tidally locked exoplanets is to use a global 3D model with a stretched mesh ...
Denis E. Sergeev +7 more
doaj +1 more source