Results 101 to 110 of about 10,220 (206)
Observations of Exoplanet Atmospheres
, 2015 Detailed characterization of an extrasolar planet's atmosphere provides the best hope for distinguishing the makeup of its outer layers, and the only hope for understanding the interplay between initial composition, chemistry, dynamics & circulation, and
Crossfield, Ian J. M.
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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
The Astronomical JournalAbstract 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 +21 more
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The Cosmic Shoreline Revisited: A Metric for Atmospheric Retention Informed by Hydrodynamic Escape
The Astrophysical JournalThe “cosmic shoreline,” a semi-empirical relation that separates airless worlds from worlds with atmospheres as proposed by K. J. Zahnle & D. C. Catling, is now guiding large-scale JWST surveys aimed at detecting rocky exoplanet atmospheres.
Xuan Ji +3 more
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Oxygen Left Behind: Atmospheric Enrichment Due to Fractionation in Sub-Neptunes Using BOREAS
The Astrophysical JournalThe 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 +3 more
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JWST/NIRISS Reveals the Water-rich “Steam World” Atmosphere of GJ 9827 d
The Astrophysical Journal LettersWith 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 +32 more
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Exoplanet Aeronomy: A Case Study of WASP-69 b’s Variable Thermosphere
The Astronomical JournalAeronomy, 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 +7 more
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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.
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Numerical Performance of Correlated-k Distribution Method in Atmospheric Escape Simulation
The Astrophysical JournalAtmospheric 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 +2 more
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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