Results 21 to 30 of about 1,751 (120)

Constraints on the Production of Phosphine by Venusian Volcanoes

Universe, 2022
The initial reports of the presence of phosphine in the cloud decks of Venus have led to the suggestion that volcanism is the source of phosphine, through volcanic phosphides ejected into the clouds. Here, we examine the idea that mantle plume volcanism,
William Bains, Oliver Shorttle, Sukrit Ranjan, Paul B. Rimmer, Janusz J. Petkowski, Jane S. Greaves, Sara Seager   +6 more
doaj   +1 more source

The erosion of large primary atmospheres typically leaves behind substantial secondary atmospheres on temperate rocky planets

Nature Communications
Exoplanet exploration has revealed that many—perhaps most—terrestrial exoplanets formed with substantial H2-rich envelopes, seemingly in contrast to solar system terrestrials, for which there is scant evidence of long-lived primary atmospheres. It is not
Joshua Krissansen-Totton, Nicholas Wogan, Maggie Thompson, Jonathan J. Fortney   +3 more
doaj   +1 more source

Solar evolution and extrema: current state of understanding of long-term solar variability and its planetary impacts

Progress in Earth and Planetary Science, 2021
The activity of stars such as the Sun varies over timescales ranging from the very short to the very long—stellar and planetary evolutionary timescales.
Dibyendu Nandy, Petrus C. H. Martens, Vladimir Obridko, Soumyaranjan Dash, Katya Georgieva   +4 more
doaj   +1 more source

Damping Obliquities of Hot Jupiter Hosts by Resonance Locking

The Astrophysical Journal Letters
When orbiting hotter stars, hot Jupiters are often highly inclined relative to their host star equator planes. By contrast, hot Jupiters orbiting cooler stars are more aligned.
J. J. Zanazzi, Janosz Dewberry, Eugene Chiang   +2 more
doaj   +1 more source

Spin and Obliquity Evolution of Hot Jupiter Hosts from Resonance Locks

The Astrophysical Journal
When a hot Jupiter orbits a star whose effective temperature exceeds ∼6100 K, its orbit normal tends to be misaligned with the stellar spin axis. Cooler stars typically have smaller obliquities, which may have been damped by hot Jupiters in resonance ...
J. J. Zanazzi, Eugene Chiang
doaj   +1 more source

Atmospheric C/O Ratios of Sub-Neptunes with Magma Oceans: Homemade rather than Inherited

The Astrophysical Journal Letters
Recently, the James Webb Space Telescope has enabled detailed spectroscopic characterization of sub-Neptune atmospheres. With detections of carbon- and oxygen-bearing species such as CO, CO _2 , CH _4 , and H _2 O, a central question is whether the ...
Aaron Werlen, Caroline Dorn, Hilke E. Schlichting, Simon L. Grimm, Edward D. Young   +4 more
doaj   +1 more source

Origin and Extent of the Opacity Challenge for Atmospheric Retrievals of WASP-39 b

The Astrophysical Journal Letters, 2023
As the James Webb Space Telescope (JWST) came online last summer, we entered a new era of astronomy. This new era is supported by data products of unprecedented information content that require novel reduction and analysis techniques.
Prajwal Niraula, Julien de Wit, Iouli E. Gordon, Robert J. Hargreaves, Clara Sousa-Silva   +4 more
doaj   +1 more source

The Effects of Non-ideal Mixing in Planetary Magma Oceans and Atmospheres

The Astrophysical Journal
Sub-Neptunes with hydrogen-rich envelopes are expected to sustain long-lived magma oceans that continuously exchange volatiles with their overlying atmospheres.
Aaron Werlen, Edward D. Young, Hilke E. Schlichting, Caroline Dorn, Anat Shahar   +4 more
doaj   +1 more source

A Census of Near-UV M-dwarf Flares Using Archival GALEX Data and the gPHOTON2 Pipeline

The Astrophysical Journal, 2023
M-dwarfs are common stellar hosts of habitable-zone exoplanets. Near-UV (NUV) radiation can severely impact the atmospheric and surface conditions of such planets, making the characterization of NUV flaring activity a key aspect in determining ...
Param Rekhi, Sagi Ben-Ami, Volker Perdelwitz, Yossi Shvartzvald   +3 more
doaj   +1 more source

Linear Thermal Instability of a Condensing Gas–Particle Mixture, with Possible Application to Chondrites and Planetesimals

The Astrophysical Journal
We study the stability of a hot saturated gas coexisting with condensed particles in an optically thin medium. Such a situation may be obtained downstream of a shock, at condensation fronts, or in vaporizing impacts. We show that the gas–particle mixture
Kecheng Stephon Qian, Eugene Chiang
doaj   +1 more source