Results 121 to 130 of about 1,575 (209)

Polycyclic Aromatic Hydrocarbons as an Extraterrestrial Atmospheric Technosignature

The 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, Ravi Kopparapu, Barbara Ercolano, Karan Molaverdikhani   +3 more
doaj   +1 more source

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

The 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, Everett Schlawin, Taylor J. Bell, Jonathan J. Fortney, Thomas G. Beatty, Thomas P. Greene, Kazumasa Ohno, Matthew M. Murphy, Vivien Parmentier, Michael R. Line, Luis Welbanks, Lindsey S. Wiser, Marcia J. Rieke   +12 more
doaj   +1 more source

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

The 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

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

The 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, Robin Wordsworth, Renyu Hu, Evgenya Shkolnik   +3 more
doaj   +1 more source

Exoplanet atmospheric characterization using amortized simulation based inference [PDF]

Around 30 years after the first exoplanet detection and over 5000 detections later, we have come a long way in characterizing a huge diversity of exoplanets to understand their formation, evolution and habitability.
Vasist, Malavika Vijayendra
core  

Evolution of Atmospheric Composition in Giant Exoplanets with Diluted Cores

Transmission spectroscopy has reported sub-solar C/O ratios (<0.55) for atmospheres of some transiting gas giants/dwarfs (e.g., Sing et al. 2024; Welbanks et al. 2024). However, static disk chemistry models (e.g., Öberg et al. 2011) predict super-solar C/O ratios for protoplanetary disk gas and, consequently, for planetary envelopes.
Matsuo, Hiroki, Kurokawa, Hiroyuki, Tokuno, Takato   +2 more
openaire   +1 more source

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

The 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, Everett Schlawin, Taylor J. Bell, Matthew M. Murphy, Thomas G. Beatty, Luis Welbanks, Thomas P. Greene, Jonathan J. Fortney, Vivien Parmentier, Isaac R. Edelman, Nishil Mehta, Marcia J. Rieke   +11 more
doaj   +1 more source

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

Structure thermique, composition, dynamique de l’atmosphère et évolution à long-terme des exoplanètes irradiées Plus d’un millier d’exoplanètes ont été découvertes depuis une dizaine d’années. Plus incroyable encore, nous pouvons maintenant caractériser les atmosphères de ces mondes lointains.
openaire   +2 more sources

The Impact of Cometary “Impacts” on the Chemistry, Climate, and Spectra of Hot Jupiter Atmospheres

The Astrophysical Journal
Impacts from icy and rocky bodies have helped shape the composition of Solar System objects; for example, the Earth–Moon system, or the recent impact of comet Shoemaker–Levy 9 with Jupiter.
F. Sainsbury-Martinez, C. Walsh
doaj   +1 more source

The Chemical Composition of Exoplanet-hosting Binary Star Systems [PDF]

, 2013
: A significant portion of stars occur as binary systems, in which two stellar components orbit a common center of mass. As the number of known exoplanet systems continues to grow, some binary systems are now known to harbor planets around one or both ...

core