Results 71 to 80 of about 581 (180)

Oxygen Left Behind: Atmospheric Enrichment Due to Fractionation in Sub-Neptunes Using BOREAS

The Astrophysical Journal
The evolution of exoplanetary atmospheres is strongly influenced by atmospheric escape, particularly for close-in planets. Fractionation during atmospheric loss can preferentially remove lighter elements such as hydrogen, while retaining heavier species ...
Marilina Valatsou, Caroline Dorn, Pierlou Marty, James E. Owen   +3 more
doaj   +1 more source

UV transit observations of EUV-heated expanded thermospheres of Earth-like exoplanets around M-stars: testing atmosphere evolution scenarios

Astrophysics and Space Science, 2011
The detection and investigation of EUV heated, extended and non-hydrostatic upper atmospheres around terrestrial exoplanets would provide important insights into the interaction of the host stars plasma environment as well as the evolution of Earth-type planets their atmospheres and possible magnetic environments.
Lammer, H., Eybl, Vera Theresa, Kislyakova, K. G., Weingrill, J., Holmstrom, M., Khodachenko, M. L., Kulikov, Yu N., Reiners, Ansgar, Leitzinger, M., Odert, P., Gruess, M. Xiang, Dorner, B. G., Guedel, M., Hanslmeier, A.   +13 more
openaire   +2 more sources

JWST/NIRISS Reveals the Water-rich “Steam World” Atmosphere of GJ 9827 d

The Astrophysical Journal Letters
With sizable volatile envelopes but smaller radii than the solar system ice giants, sub-Neptunes have been revealed as one of the most common types of planet in the galaxy. While the spectroscopic characterization of larger sub-Neptunes (2.5–4 R _⊕ ) has
Caroline Piaulet-Ghorayeb, Björn Benneke, Michael Radica, Eshan Raul, Louis-Philippe Coulombe, Eva-Maria Ahrer, Daria Kubyshkina, Ward S. Howard, Joshua Krissansen-Totton, Ryan J. MacDonald, Pierre-Alexis Roy, Amy Louca, Duncan Christie, Marylou Fournier-Tondreau, Romain Allart, Yamila Miguel, Hilke E. Schlichting, Luis Welbanks, Charles Cadieux, Caroline Dorn, Thomas M. Evans-Soma, Jonathan J. Fortney, Raymond Pierrehumbert, David Lafrenière, Lorena Acuña, Thaddeus Komacek, Hamish Innes, Thomas G. Beatty, Ryan Cloutier, René Doyon, Anna Gagnebin, Cyril Gapp, Heather A. Knutson   +32 more
doaj   +1 more source

EXODUS: A mission to explore exoplanet evolution through understanding atmospheric escape

EXODUS is a proposed mission to study the largely unexplored range of sub-Neptune to Jupiter-sized exoplanets with orbital periods longer than 100 days. The focus of the mission lies in the detection of these planets and characterisation of atmospheric escape to constrain their evolutionary pathways.
Citlali Bruce Rosete, Mireia Leon Dasi, Marius Anger, Paula Benitez Sesmilo, Mark R. Boyd, Frederik Dall'Omo, Simone Filomeno, Jan-Vincent Harre, Kim Angelique Kahle, Isabel Pitz, Vito Saggese   +10 more
openaire   +2 more sources

Exoplanet Aeronomy: A Case Study of WASP-69 b’s Variable Thermosphere

The Astronomical Journal
Aeronomy, the study of Earth’s upper atmosphere and its interaction with the local space environment, has long traced changes in the thermospheres of Earth and other solar system planets to solar variability in the X-ray and extreme-ultraviolet ...
W. Garrett Levine, Shreyas Vissapragada, Adina D. Feinstein, George W. King, Aleck Hernandez, Lía Corrales, Michael Greklek-McKeon, Heather A. Knutson   +7 more
doaj   +1 more source

Atmospheric Studies of brown-Dwarfs and Exoplanets: Insights into Planet Formation and Evolution

, 2018
Cette thèse se focalise sur les propriétés atmosphériques des exoplanètes et des naines brunes et le lien avec les mécanismes de formation. Dans la première partie, le ratio des abondances de carbone et d'oxygène (C/O) du compagnon et de son étoile hôte est utilisé comme proxy.
openaire   +1 more source

Signatures of Atmospheric Mass Loss and Planet Migration in the Time Evolution of Short-period Transiting Exoplanets

The Astronomical Journal
Abstract Comparative studies of young and old exoplanet populations offer a glimpse into how planets may form and evolve with time. We present an occurrence rate study of short-period (<12 days) planets between 1.8 and 10 R ⊕ around 1374 FGK stars in nearby (200 pc) young clusters (<1 Gyr), utilizing data from the
Rachel B. Fernandes, Galen J. Bergsten, Gijs D. Mulders, Ilaria Pascucci, Kevin K. Hardegree-Ullman, Steven Giacalone, Jessie L. Christiansen, James G. Rogers, Akash Gupta, Rebekah I. Dawson, Tommi T. Koskinen, Kiersten M. Boley, Jason L. Curtis, Katia Cunha, Eric E. Mamajek, Sabina Sagynbayeva, Sakhee S. Bhure, David R. Ciardi, Preethi R. Karpoor, Kyle A. Pearson, Jon K. Zink, Gregory A. Feiden   +21 more
openaire   +4 more sources

Numerical Performance of Correlated-k Distribution Method in Atmospheric Escape Simulation

The Astrophysical Journal
Atmospheric escape is crucial to understanding the evolution of planets in and out of the solar system and to interpreting atmospheric observations. While hydrodynamic escape simulations have been actively developed incorporating detailed processes such ...
Yuichi Ito, Tatsuya Yoshida, Akifumi Nakayama   +2 more
doaj   +1 more source

Coupling the Secular Dynamical and Atmospheric Evolution of Close-in Exoplanets

This thesis plunges into the enigmatic formation of the hot Neptune desert, a sparsely populated region of exoplanetary demographics, by exploring the processes that shape close-in exoplanets. Central to this inquiry is the interplay between atmospheric evaporation and orbital migration, two pivotal mechanisms governing the evolution of planetary ...
openaire   +2 more sources

Blowin’ in the Nonisothermal Wind: Core-powered Mass Loss with Hydrodynamic Radiative Transfer

The Astrophysical Journal
The 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, Matthäus Schulik, Hilke E. Schlichting, James E. Owen   +3 more
doaj   +1 more source