Results 41 to 50 of about 9,607 (187)

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

The 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

On the existence of energetic atoms in the upper atmosphere of exoplanet HD209458b [PDF]

, 2010
Stellar irradiation and particles forcing strongly affect the immediate environment of extrasolar giant planets orbiting near their parent stars. Here, we use far-ultraviolet emission spectra from HD209458 in the wavelength range (1180-1710)A to bring ...
Ben-Jaffel, Ben-Jaffel, Ben-Jaffel, Charbonneau, Cranmer, Cranmer, Gu, Henry, Ip, Knutson, Lotfi Ben-Jaffel, Moos, Murray-Clay, Ratkiewicz, S. Sona Hosseini, Sanchez-Lavego, Schneiter, Shkolnik, Stone, Tian, Vidal-Madjar, Wood, Wood   +22 more
core   +2 more sources

Sub-Neptunes Are Drier than They Seem: Rethinking the Origins of Water-rich Worlds

The Astrophysical Journal Letters
Recent claims of biosignature gases in sub-Neptune atmospheres have renewed interest in water-rich sub-Neptunes with surface oceans, often referred to as Hycean planets. These planets are hypothesized to form beyond the snow line, accreting large amounts
Aaron Werlen, Caroline Dorn, Remo Burn, Hilke E. Schlichting, Simon L. Grimm, Edward D. Young   +5 more
doaj   +1 more source

The Runaway Greenhouse Effect on Hycean Worlds

The 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, Shang-Min Tsai, Raymond T. Pierrehumbert   +2 more
doaj   +1 more source

Infrared Observations During the Secondary Eclipse of HD 209458b: I. 3.6-Micron Occultation Spectroscopy Using the VLT [PDF]

, 2002
We search for an infrared signature of the transiting extrasolar planet HD 209458b during secondary eclipse. Our method, which we call `occultation spectroscopy,' searches for the disappearance and reappearance of weak spectral features due to the ...
Brown L. R., Cedric Goukenleuque, David Steyert, Drake Deming, Guenter Wiedemann, Joseph Harrington, L. Jeremy Richardson, Larry W. Esposito, Perryman M. A. C., Sawyer S. R.   +9 more
core   +3 more sources

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

The Bochum Survey of the Southern Galactic Disk: III. Complete Data Release

Astronomische Nachrichten, Volume 347, Issue 3, March 2026.
ABSTRACT The Southern Galactic Disk Survey (GDS) monitored a mosaic of 268 fields along a 6°$$ {6}^{{}^{\circ}} $$‐wide stripe in the southern Galactic disk with simultaneous observations in r′$$ {r}^{\prime } $$ and i′$$ {i}^{\prime } $$ (7m≲r′,i′≲18m$$ {7}^{\mathrm{m}}\lesssim {r}^{\prime },{i}^{\prime}\lesssim {18}^{\mathrm{m}} $$) from September ...
Julia Blex, Moritz Hackstein, Christian Westhues, Michael Ramolla, Markus Demleitner, Dominik J. Bomans, Kerstin Weis, Christofer Fein, Rolf Chini   +8 more
wiley   +1 more source

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

The 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

Bayesian analysis of interiors of HD 219134b, Kepler-10b, Kepler-93b, CoRoT-7b, 55 Cnc e, and HD 97658b using stellar abundance proxies [PDF]

, 2016
Using a generalized Bayesian inference method, we aim to explore the possible interior structures of six selected exoplanets for which planetary mass and radius measurements are available in addition to stellar host abundances: HD~219134b, Kepler-10b ...
Dorn, C., Hinkel, N. R., Venturini, J.
core   +2 more sources

Effects of Hydrogen on Fe‐S Alloys and Their Implications for the Martian Core

Journal of Geophysical Research: Planets, Volume 131, Issue 3, March 2026.
Abstract Meteorites suggest the Martian core comprises iron (Fe) or iron‐nickel (Fe‐Ni) alloy with sulfur (S) identified as the primary light element. The InSight data revealed a larger, less dense Martian core than previously estimated, indicating additional light elements.
Xuehui Wei, Stella Chariton, Vitali B. Prakapenka, Yingwei Fei, Sang‐Heon Shim   +4 more
wiley   +1 more source