Results 11 to 20 of about 3,427 (167)
The Nature and Origins of Sub-Neptune Size Planets. [PDF]
J Geophys Res Planets, 2021 Abstract Planets intermediate in size between the Earth and Neptune, and orbiting closer to their host stars than Mercury does the Sun, are the most common type of planet revealed by exoplanet surveys over the last quarter century. Results from NASA's Kepler mission have revealed a bimodality in the radius distribution of these objects, with a relative
Bean JL, Raymond SN, Owen JE.
europepmc +2 more sources
Geophysical Research Letters, Volume 50, Issue 5, 16 March 2023., 2023 Abstract Although high pressure enables alloying between hydrogen and iron, hydrogen‐to‐iron molar ratio (H/Fe) so far found in experiments is mostly limited to 1 in the close‐packed iron metal under high pressure. We report a H/(Fe + Ni) ratio of 1.8 ± 0.1 from (Fe,Ni)Hx (or x ≥ 1.8) quenched from liquid, exceeding the amounts so far reported for ...
Hélène Piet +7 more
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The harsh environment where exoplanets live
Astronomische Nachrichten, Volume 343, Issue 4, May 2022., 2022 Abstract The X‐ray and Extreme Ultraviolet (XUV) actvity of the Sun has determined important effects on the planets around it. In particular, high doses of X‐rays, flares, and coronal mass ejections (CMEs) combined with masses and sizes of the planets and the shielding action of the planetary magnetic fields have determined the diverse habitability of ...
Ignazio Pillitteri
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AGU Advances, Volume 3, Issue 1, February 2022., 2022 Abstract Volatile compositions of asteroids provide information on the Solar System history and the origins of Earth's volatiles. Visible to near‐infrared observations at wavelengths of <2.5 µm have suggested a genetic link between outer main belt asteroids located at 2.5–4 au and carbonaceous chondrite meteorites (CCs) that show isotopic similarities ...
H. Kurokawa +6 more
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1I/‘Oumuamua as an N2 Ice Fragment of an exo‐Pluto Surface: I. Size and Compositional Constraints
Journal of Geophysical Research: Planets, Volume 126, Issue 5, May 2021., 2021 Abstract The origin of the interstellar object 1I/‘Oumuamua has defied explanation. We perform calculations of the non‐gravitational acceleration that would be experienced by bodies composed of a range of different ices and demonstrate that a body composed of N2 ice would satisfy the available constraints on the non‐gravitational acceleration, size ...
Alan P. Jackson, Steven J. Desch
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Journal of Geophysical Research: Planets, Volume 126, Issue 5, May 2021., 2021 Abstract The origin of the interstellar object 1I/‘Oumuamua has defied explanation. In a companion paper (Jackson & Desch, 2021), we show that a body of N2 ice with axes 45 m × 44 m × 7.5 m at the time of observation would be consistent with its albedo, nongravitational acceleration, and lack of observed CO or CO2 or dust.
S. J. Desch, A. P. Jackson
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Hot Jupiters: Origins, Structure, Atmospheres
Journal of Geophysical Research: Planets, Volume 126, Issue 3, March 2021., 2021 Abstract We provide a brief review of many aspects of the planetary physics of hot Jupiters. Our aim is to cover most of the major areas of current study while providing the reader with additional references for more detailed follow‐up. We first discuss giant planet formation and subsequent orbital evolution via disk‐driven torques or dynamical ...
Jonathan J. Fortney +2 more
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Journal of Geophysical Research: Planets, Volume 126, Issue 2, February 2021., 2021 Abstract The earliest atmospheres of rocky planets originate from extensive volatile release during magma ocean epochs that occur during assembly of the planet. These establish the initial distribution of the major volatile elements between different chemical reservoirs that subsequently evolve via geological cycles.
Tim Lichtenberg +6 more
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A correlation between the heavy element content of transiting extrasolar planets and the metallicity of their parent stars [PDF]
, 2006 Nine extrasolar planets with masses between 110 and 430M are known to transit their star. The knowledge of their masses and radii allows an estimate of their composition, but uncertainties on equations of state, opacities and possible missing energy ...
Alibert +39 more
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The Astronomical Journal, 2022 We present an estimate of the occurrence rate of hot Jupiters (7 R _⊕ ≤ R _p ≤ 2 R _J , 0.8 ≤ P _b ≤ 10 days) around early-type M dwarfs based on stars observed by the Transiting Exoplanet Survey Satellite (TESS) during its primary mission.
Tianjun Gan +28 more
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