Results 71 to 80 of about 193,103 (196)

Novel Graphitic Oxynitrides as Photocatalysts for Sustainable H2 Production and CO2 Valorization. The Importance of Self‐Assembly for Catalytic Activity

ChemSusChem, Volume 18, Issue 3, February 1, 2025.
A novel subclass of graphitic oxynitrides, easily generated from otherwise abundant prebiotic monomers, namely cyanamide and glyoxal, debut in the scenario of sustainable heterogeneous catalysts, as demonstrated through applications to the highly demanding H2 and CO2 agendas.
Nieves Lavado, Rosario Pardo‐Botello, José María Sánchez‐Rodas, R. Fernando Martínez, Vicente Montes, Francisco Javier López‐Tenllado, Pedro Cintas, Reyes Babiano   +7 more
wiley   +1 more source

Helium Atmospheres on Warm Neptune- and Sub-Neptune-Sized Exoplanets and Applications to GJ 436 b [PDF]

arXiv, 2015
Warm Neptune- and sub-Neptune-sized exoplanets in orbits smaller than Mercury's are thought to have experienced extensive atmospheric evolution. Here we propose that a potential outcome of this atmospheric evolution is the formation of helium-dominated atmospheres.
arxiv  

Initial Thermal States of Super‐Earth Exoplanets and Implications for Early Dynamos

Journal of Geophysical Research: Planets, Volume 130, Issue 2, February 2025.
Abstract The accretion of Earth and the formation of a metallic core released a large amount of primordial heat and may have enabled its evolution into a habitable world. Metal‐silicate segregation likely occurs in super‐Earth exoplanets as well, but its influence on their initial thermal states has not been fully examined.
Nathaniel I. White, Jie Li
wiley   +1 more source

Where Are the Water Worlds? Identifying Exo-water-worlds Using Models of Planet Formation and Atmospheric Evolution

The Astrophysical Journal
Planet formation models suggest that the small exoplanets that migrate from beyond the snowline of the protoplanetary disk likely contain water-ice-rich cores (∼50% by mass), also known as water worlds.
Aritra Chakrabarty, Gijs D. Mulders
doaj   +1 more source

Spectra as Windows into Exoplanet Atmospheres [PDF]

, 2013
Understanding a planet's atmosphere is a necessary condition for understanding not only the planet itself, but also its formation, structure, evolution, and habitability, This puts a premium on obtaining spectra, and developing credible interpretative tools with which to retrieve vital planetary information. However, for exoplanets these twin goals are
arxiv   +1 more source

MARVEL Analysis of High‐Resolution Rovibrational Spectra of 16O13C18O

Journal of Computational Chemistry, Volume 46, Issue 1, January 5, 2025.
12348 measured transitions in the wavenumber range 578–9318 cm−1 for carbon dioxide (isotopologue 638) were used° to calculating 3975 empirical rovibrational energy levels with J° up to 82. ABSTRACT A large set of validated experimental transitions and empirical rovibrational energy levels are reported for the fifth most abundant carbon dioxide ...
Ala'a A. A. Azzam, Jonathan Tennyson, Sergei N. Yurchenko, Tibor Furtenbacher, Attila G. Császár   +4 more
wiley   +1 more source

Helium in the Extended Atmosphere of the Warm Superpuff TOI-1420b

The Astronomical Journal
Superpuffs are planets with exceptionally low densities ( ρ ≲ 0.1 g cm ^−3 ) and core masses ( M _c ≲ 5 M _⊕ ). Many lower-mass ( M _p ≲ 10 M _⊕ ) superpuffs are expected to be unstable to catastrophic mass loss via photoevaporation and/or boil-off ...
Shreyas Vissapragada, Michael Greklek-McKeon, Dion Linssen, Morgan MacLeod, Daniel P. Thorngren, Peter Gao, Heather A. Knutson, David W. Latham, Mercedes López-Morales, Antonija Oklopčić, Jorge Pérez González, Morgan Saidel, Abigail Tumborang, Stephanie Yoshida   +13 more
doaj   +1 more source

Understanding Exoplanet Atmospheres with UV Observations II: The Far UV and Atmospheric Escape [PDF]

arXiv, 2019
Much of the focus of exoplanet atmosphere analysis in the coming decade will be at infrared wavelengths, with the planned launches of the James Webb Space Telescope (JWST) and the Wide-Field Infrared Survey Telescope (WFIRST). However, without being placed in the context of broader wavelength coverage, especially in the optical and ultraviolet ...
arxiv  

How black hole activity may influence exoplanetary evolution in our Galaxy [PDF]

2024, MNRAS, 533, 455
An increasing number of exoplanets have been discovered in the Milky Way galaxy, which is also known to harbour a super-massive black hole (Sagittarius A*) at its centre. Here, we investigate how the central black hole (BH) activity may affect the evolution of exoplanets in our Galaxy. Accreting BHs emit high-energy radiation -- extreme ultraviolet and
arxiv   +1 more source

White Dwarf Stars in the Big Data Era

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT White dwarf stars are the most common endpoint of stellar evolution. Therefore, these old, numerous and compact objects provide valuable information on the late stages of stellar evolution, the physics of dense plasma and the structure and evolution of our Galaxy.
Maria Camisassa
wiley   +1 more source