Results 111 to 120 of about 8,946 (200)

A Photochemical Phosphorus-Hydrogen-Oxygen Network for Hydrogen-dominated Exoplanet Atmospheres

open access: yesThe Astrophysical Journal
Due to the detection of phosphine (PH _3 ) in the solar system gas giants Jupiter and Saturn, PH _3 has long been suggested to be detectable in exosolar substellar atmospheres too.
Elspeth K. H. Lee   +5 more
doaj   +1 more source

The Solubility of N2 in High-pressure Ice and Its Consequent Outgassing Limitations in Water Worlds

open access: yesThe Astrophysical Journal
Exoplanets with a few percent water mass fraction may host a high-pressure ice layer that separates the atmosphere from the interior. We investigate the role played by this layer in the transport of N _2 between the interior and the atmosphere.
Amit Levi   +3 more
doaj   +1 more source

NASA’s Pandora SmallSat Mission: Simulated Modeling and Retrieval of Near-infrared Exoplanet Transmission Spectra

open access: yesThe Astronomical Journal
Pandora is a SmallSat mission dedicated to understanding exoplanets and their host stars by disentangling the impact of stellar heterogeneity on exoplanet transmission spectra.
Yoav Rotman   +24 more
doaj   +1 more source

Polycyclic Aromatic Hydrocarbons as an Extraterrestrial Atmospheric Technosignature

open access: yesThe Planetary Science Journal
Polycyclic aromatic hydrocarbons (PAHs) are prevalent in the Universe and interstellar medium but are primarily attributed to anthropogenic sources on Earth, such as fossil fuel combustion and firewood burning.
Dwaipayan Dubey   +3 more
doaj   +1 more source

Retrieval of atmospheric structure and composition of exoplanets from transit spectroscopy

open access: yes, 2016
Recent spectroscopic observations of transiting exoplanets have permitted the derivation of the thermal structure and molecular abundances of H2O, CO, CO2, CH4, metallic oxides and alkali metals in these extreme atmospheres. Here, for the first time, a fully-fledged retrieval algorithm has been applied to exoplanet spectra to determine the thermal ...
openaire   +1 more source

A JWST Panchromatic Thermal Emission Spectrum of the Warm Neptune Archetype GJ 436b

open access: yesThe Astrophysical Journal Letters
GJ 436b is the archetype warm Neptune exoplanet. The planet’s thermal emission spectrum was previously observed via intensive secondary eclipse campaigns with Spitzer.
Sagnick Mukherjee   +12 more
doaj   +1 more source

Atmospheric Chemistry of Secondary and Hybrid Atmospheres of Super Earths and Sub-Neptunes

open access: yesThe Astrophysical Journal
The atmospheres of small exoplanets likely derive from a combination of geochemical outgassing and primordial gases left over from formation. Secondary atmospheres, such as those of Earth, Mars, and Venus, are sourced by outgassing. Persistent outgassing
Meng Tian, Kevin Heng
doaj   +1 more source

A Possible Metal-dominated Atmosphere below the Thick Aerosols of GJ 1214 b Suggested by Its JWST Panchromatic Transmission Spectrum

open access: yesThe Astrophysical Journal Letters
GJ 1214b is the archetype sub-Neptune for which thick aerosols have prevented us from constraining its atmospheric properties for over a decade. In this study, we leverage the panchromatic transmission spectrum of GJ 1214b established by the Hubble Space
Kazumasa Ohno   +11 more
doaj   +1 more source

Strong Fractionation of Deuterium and Helium in Sub-Neptune Atmospheres along the Radius Valley

open access: yesThe Astrophysical Journal
We simulate atmospheric fractionation in escaping planetary atmospheres using IsoFATE , a new open-source numerical model. We expand the parameter space studied previously to planets with tenuous atmospheres that exhibit the greatest helium and deuterium
Collin Cherubim   +3 more
doaj   +1 more source

Thermal structure, composition, atmospheric dynamics and long-terme evolution of irradiated exoplanets

open access: yes, 2014
More than a thousand exoplanets have been discovered over the last decade. Perhaps more excitingly, probing their atmospheres has become possible. We now have spectra of hot Jupiters like HD 189733b and HD 209458b, of Neptune-like planets like GJ1214b and even smaller planets are within reach.
openaire   +1 more source

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