Results 21 to 30 of about 517 (155)

Nitrogen as a Tracer of Giant Planet Formation. II. Comprehensive Study of Nitrogen Photochemistry and Implications for Observing NH3 and HCN in Transmission and Emission Spectra

open access: yesThe Astrophysical Journal, 2023
Atmospheric nitrogen may provide important constraints on giant planet formation. Following our semianalytical work, we further pursue the relation between observable NH _3 and an atmosphere’s bulk nitrogen abundance by applying the photochemical ...
Kazumasa Ohno, Jonathan J. Fortney
doaj   +1 more source

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

open access: yesThe 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   +4 more
doaj   +1 more source

Thermoelastic Contraction as a Suppressor of Atmospheric Escape in Close-in Exoplanets

open access: yesThe Astrophysical Journal
The survival of volatile-rich atmospheres on close-in exoplanets challenges classical escape models. We identify a fully classical, interior-driven correction: thermoelastic contraction of the planetary mantle slightly increases the gravitational binding
L. Yıldız, D. Kaykı, E. Güdekli
doaj   +1 more source

Effect of Laboratory Reagents for Cleaning Modern Contamination on the δ15N Integrity of Nitrogen‐Poor Samples

open access: yesRapid Communications in Mass Spectrometry, Volume 40, Issue 19, 15 October 2026.
ABSTRACT Rationale Nitrogen isotope values have been widely used for tracing ancient biogeochemical processes, but contaminant‐sensitive materials, such as Precambrian sedimentary rocks, meteorites, or returned extraterrestrial samples, often have low nitrogen levels and are thus vulnerable to modern organic contamination.
Kunmanee Bubphamanee   +2 more
wiley   +1 more source

The Role of Formation Location in Shaping Sulfur-, Nitrogen-, and Carbon-bearing Species in Super-Earth and Sub-Neptune Atmospheres

open access: yesThe Astrophysical Journal
Atmospheric compositions of sub-Neptunes and super-Earths are often interpreted as tracers of formation location relative to volatile ice lines. However, prolonged magma oceans can chemically equilibrate with primordial atmospheres and modify accreted ...
Aaron Werlen   +4 more
doaj   +1 more source

The Runaway Greenhouse Effect on Hycean Worlds

open access: yesThe Astrophysical Journal, 2023
Hycean worlds are a proposed subset of sub-Neptune exoplanets with substantial water inventories, liquid surface oceans, and extended hydrogen-dominated atmospheres favorable for habitability.
Hamish Innes   +2 more
doaj   +1 more source

Massive Rocky Planets May Suppress Deep Melting

open access: yesAGU Advances, Volume 7, Issue 4, August 2026.
Abstract Melting properties of silicates are critical to understanding the thermal evolution of rocky planetary interiors. In the deep mantles of massive rocky planets, post‐post‐spinel Mg2SiO4 ${\text{Mg}}_{2}{\text{SiO}}_{4}$ is potentially one of the most abundant mineral phases, yet its melting behavior remains unconstrained. Here, we determine the
Donghao Zheng, Yihang Peng, Jie Deng
wiley   +1 more source

Helium Escape in Context: Comparative Signatures of Four Close-in Exoplanets

open access: yesThe Astrophysical Journal
Observations of escaping atmospheres on close-in exoplanets show a wide range in the strength and morphology of He I 10830 Å and H I absorption. Scaling relations attempt to link the He I signal to X-ray and UV irradiation, mass loss, and bulk planetary ...
Anna Ruth Taylor   +4 more
doaj   +1 more source

Interactions of Sublimated Frost With Volcanic Plumes: Modeling Io's SO2 Atmosphere Using the DSMC Method

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 7, July 2026.
Abstract Io's tenuous atmosphere consists primarily of sulfur dioxide (SO2 ${\text{SO}}_{2}$) with observed column densities of approximately 1016−1017 $1{0}^{16}-1{0}^{17}$ cm−2 ${\text{cm}}^{-2}$. However, it remains uncertain whether the sublimation of SO2 ${\text{SO}}_{2}$ surface frost or volcanic outgassing is the primary source of the SO2 ...
Leander Schlarmann   +4 more
wiley   +1 more source

A Panchromatic Characterization of the Evening and Morning Atmosphere of WASP-107 b: Composition and Cloud Variations, and Insight into the Effect of Stellar Contamination

open access: yesThe Astronomical Journal
Limb-resolved transmission spectroscopy has the potential to transform our understanding of exoplanetary atmospheres. By separately measuring the transmission spectra of the evening and morning limbs, these atmospheric regions can be individually ...
Matthew M. Murphy   +18 more
doaj   +1 more source

Home - About - Disclaimer - Privacy