Results 11 to 20 of about 372,922 (156)
The Nature and Origins of Sub-Neptune Size Planets. [PDF]
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
General circulation modelling of close-in extrasolar giant planets [PDF]
PhDA large fraction of the extrasolar planets detected so far are giant planets that have such short orbital periods (a few days) that they are thought to be tidally-synchronised with the host star. Such orbits lead to permanent day/night sides on the
Thrastarson, Heidar Thor
core +4 more sources
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
wiley +1 more source
The harsh environment where exoplanets live
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
wiley +1 more source
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
wiley +1 more source
1I/‘Oumuamua as an N2 Ice Fragment of an exo‐Pluto Surface: I. Size and Compositional Constraints
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
wiley +1 more source
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
wiley +1 more source
Hot Jupiters: Origins, Structure, Atmospheres
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
wiley +1 more source
Disk evolution, element abundances and cloud properties of young gas giant planets. [PDF]
ChHc and PBR highlights financial support of the European Community under the FP7 program by an ERC starting grant. PW, IK, and WFT acknowledge funding from the European Union Seventh Framework Programme FP7-2011 under grant agreement No.
Helling C +5 more
europepmc +3 more sources
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
wiley +1 more source

