Results 41 to 50 of about 10,991 (143)

Magma Ocean Evolution at Arbitrary Redox State

Journal of Geophysical Research: Planets, Volume 129, Issue 12, December 2024.
Abstract Interactions between magma oceans and overlying atmospheres on young rocky planets leads to an evolving feedback of outgassing, greenhouse forcing, and mantle melt fraction. Previous studies have predominantly focused on the solidification of oxidized Earth‐similar planets, but the diversity in mean density and irradiation observed in the low ...
Harrison Nicholls, Tim Lichtenberg, Dan J. Bower, Raymond Pierrehumbert   +3 more
wiley   +1 more source

Amplifying Resonant Repulsion with Inflated Young Planets, Overlooked Inner Planets, and Nonzero Initial Δ

The Astrophysical Journal
Most multiplanet systems around mature (∼5 Gyr old) host stars are nonresonant. Even the near-resonant planet pairs still display 1%–2% positive deviation from perfect period commensurabilities (Δ) near first-order mean motion resonances (MMRs). Resonant
Yuancheng Xu, Fei Dai
doaj   +1 more source

The Venus Global Ionosphere‐Thermosphere Model (V‐GITM): A Coupled Thermosphere and Ionosphere Formulation

Journal of Geophysical Research: Planets, Volume 129, Issue 7, July 2024.
Abstract This paper introduces the new Venus global ionosphere‐thermosphere model (V‐GITM) which incorporates the terrestrial GITM framework with Venus‐specific parameters, ion‐neutral chemistry, and radiative processes in order to simulate some of the observable features regarding the temperatures, composition, and dynamical structure of the Venus ...
Brandon M. Ponder, Aaron J. Ridley, Stephen W. Bougher, David Pawlowski, Amanda Brecht   +4 more
wiley   +1 more source

Are WASP-107-like Systems Consistent with High-eccentricity Migration?

The Astrophysical Journal
WASP-107 b seems to be a poster child of the long-suspected high-eccentricity migration scenario. It is on a 5.7 day, polar orbit. The planet is Jupiter-like in radius but Neptune-like in mass with exceptionally low density.
Hang Yu, Fei Dai
doaj   +1 more source

Constraining stellar tidal quality factors from planet‐induced stellar spin‐up

Astronomische Nachrichten, Volume 345, Issue 5, June 2024.
Abstract The dynamical evolution of tight star‐planet systems is influenced by tidal interactions between the star and the planet, as was shown recently. The rate at which spins and orbits in such a system evolve depends on the stellar and planetary tidal dissipation efficiency. Here, we present a method to constrain the modified tidal quality factor Q*
Nikoleta Ilić, Katja Poppenhaeger, Anna Barbara Queiroz, Cristina Chiappini   +3 more
wiley   +1 more source

An Empirical Predictive Model for Atmospheric H Lyman‐α Emission Brightness at Mars

Earth and Space Science, Volume 11, Issue 6, June 2024.
Abstract Characterizing the abundance of atmospheric hydrogen (H) at Mars is critical for determining the current and, subsequently, the primordial water content on the planet. At present, the atmospheric abundance of Martian H is not directly measured but is simulated using proprietary models that are constrained with observations of H Lyman‐α ...
Majd Mayyasi, Adil Mayyasi
wiley   +1 more source

Different Planetary Eccentricity-period (PEP) Distributions of Small and Giant Planets

The Astronomical Journal
We used the database of 1040 short-period (1 ≤ P < 200 days) exoplanets radial-velocity orbits to study the planetary eccentricity-period (PEP) distribution.
Dolev Bashi, Tsevi Mazeh, Simchon Faigler   +2 more
doaj   +1 more source

A Verification Suite of Test Cases for the Barotropic Solver of Ocean Models

Journal of Advances in Modeling Earth Systems, Volume 16, Issue 4, April 2024.
Abstract The development of any atmosphere or ocean model warrants a suite of test cases (TCs) to verify its spatial and temporal discretizations, order of accuracy, stability, reproducibility, portability, scalability, etc. In this paper, we present a suite of shallow water TCs designed to verify the barotropic solver of atmosphere and ocean models ...
Siddhartha Bishnu, Mark R. Petersen, Bryan Quaife, Joseph Schoonover   +3 more
wiley   +1 more source

Kepler-discovered Multiple-planet Systems near Period Ratios Suggestive of Mean-motion Resonances Are Young

The Astronomical Journal
Before the launch of the Kepler Space Telescope, models of low-mass planet formation predicted that convergent type I migration would often produce systems of low-mass planets in low-order mean-motion resonances.
Jacob H. Hamer, Kevin C. Schlaufman
doaj   +1 more source

Exomoon Phase Curves: Toroidal Exosphere Simulations of Exo‐Ios Orbiting 8 Exoplanets in Alkali Spectroscopy

Journal of Geophysical Research: Planets, Volume 129, Issue 3, March 2024.
Abstract Toroidal atmospheres and exospheres characterized at exoplanets may be fueled by volcanically active exomoons, often referred to as exo‐Ios. We study the neutral outgassing and volatile evolution of a close‐orbiting, evaporating satellite at eight candidate exoplanet‐exomoon systems WASP‐49,‐96,‐69,‐17 b, XO‐2N b, HAT‐P‐1 b, HD‐189733 b, and ...
M. Meyer zu Westram, A. V. Oza, A. Galli
wiley   +1 more source