Results 81 to 90 of about 40,892 (232)

A Unified Treatment of Kepler Occurrence to Trace Planet Evolution. II. The Radius Cliff Formed by Atmospheric Escape

open access: yesThe Astronomical Journal
The Kepler mission enabled us to look at the intrinsic population of exoplanets within our galaxy. In period-radius space, the distribution of the intrinsic population of planets contains structure that can trace planet formation and evolution history ...
Anne Dattilo, Natalie M. Batalha
doaj   +1 more source

Variability of Known Exoplanet Host Stars Observed by TESS

open access: yesThe Astronomical Journal, 2023
Both direct and indirect methods of exoplanet detection rely upon detailed knowledge of the potential host stars. Such stellar characterization allows for accurate extraction of planetary properties, as well as contributing to our overall understanding ...
Emilie R. Simpson   +5 more
doaj   +1 more source

A New Set of Atmosphere and Evolution Models for Brown Dwarfs and Giant Exoplanets

open access: yes, 2019
The study of brown dwarfs and giant exoplanets is rapidly evolving as ever-improving instrumentation becomes sensitive to cooler objects. Accurate and reliable atmosphere and evolutionary models are important for placing mass and age constraints on these newly discovered objects, and understanding the rich chemistry and physics taking place in their ...
Mark W Phillips   +3 more
openaire   +2 more sources

On the protection of extrasolar Earth-like planets around K/M stars against galactic cosmic rays

open access: yes, 2009
Previous studies have shown that extrasolar Earth-like planets in close-in habitable zones around M-stars are weakly protected against galactic cosmic rays (GCRs), leading to a strongly increased particle flux to the top of the planetary atmosphere.
A. Stadelmann   +64 more
core   +3 more sources

Field‐Aligned Currents and Auroral Precipitation During the Terrestrial Alfvén Wing State

open access: yesGeophysical Research Letters, Volume 52, Issue 12, 28 June 2025.
Abstract When sub‐Alfvénic (Alfvén Mach number MA< ${\mathrm{M}}_{A}< $1) plasmas impact Earth, Alfvén wings (AWs) develop. A Multiscale Atmosphere Geospace Environment simulation of the April 2023 storm, validated by Active Magnetosphere and Planetary Electrodynamics Response Experiment data, reveals the field‐aligned‐current (FAC) generation ...
B. L. Burkholder   +5 more
wiley   +1 more source

Effects of Planetary Parameters on Disequilibrium Chemistry in Irradiated Planetary Atmospheres: From Gas Giants to Sub-Neptunes

open access: yesThe Astrophysical Journal
A primary goal of characterizing exoplanet atmospheres is to constrain planetary bulk properties, such as their metallicity, C/O ratio, and intrinsic heat.
Sagnick Mukherjee   +4 more
doaj   +1 more source

Decomposition of Benzene during Impacts in N2-dominated Atmospheres

open access: yesThe Astrophysical Journal, 2023
Benzene is a simple neutral aromatic compound found in molecular clouds, comets, and planetary atmospheres. It has been confirmed on Jupiter, Saturn, Titan, and is expected on exoplanets.
Lukáš Petera   +3 more
doaj   +1 more source

Ion Escape From Degenerate Induced Magnetospheres: The Case of Mars

open access: yesGeophysical Research Letters, Volume 52, Issue 12, 28 June 2025.
Abstract When the cone angle of the interplanetary magnetic field (IMF) becomes small, induced magnetospheres of unmagnetized planets degenerate. Using hybrid simulations, we study ionospheric ion escape in a 4° cone angle case and compare it with the nominal 55° cone angle (Parker spiral) case. The total escape rate is 1.7×1025 $1.7\times 1{0}^{25}$ s−
Qi Zhang   +7 more
wiley   +1 more source

A High-resolution Non-detection of Escaping Helium in the Ultrahot Neptune LTT 9779b: Evidence for Weakened Evaporation

open access: yesThe Astrophysical Journal Letters
The recent discovery of “ultrahot” ( P < 1 day) Neptunes has come as a surprise: some of these planets have managed to retain gaseous envelopes despite being close enough to their host stars to trigger strong photoevaporation and/or Roche lobe overflow ...
Shreyas Vissapragada   +18 more
doaj   +1 more source

Planetary Parameters, XUV Environments, and Mass-loss Rates for Nearby Gaseous Planets with X-Ray-detected Host Stars

open access: yesThe Astronomical Journal, 2023
We leverage Gaia DR2 parallactic distances to deliver new or revised estimates of planetary parameters and X-ray irradiation for a distance-limited (≲100 pc) sample of 27 gaseous planets (from super-Earths to hot Jupiters) with publicly available Chandra
Riccardo Spinelli   +6 more
doaj   +1 more source

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