Results 51 to 60 of about 700,042 (263)

Measuring titanium isotope ratios in exoplanet atmospheres [PDF]

Astronomy & Astrophysics, 2021
[abridged] Measurements of relative isotope abundances can provide unique insights into the formation and evolution histories of celestial bodies. The five stable isotopes of titanium are used to study the early history of the solar system and constrain ...
Dilovan B. Serindag, I. Snellen, P. Mollière   +2 more
semanticscholar   +1 more source

Nonthermal Atmospheric Escape on the Kepler-11 “Super-Earths” Driven by Stellar Wind Sputtering

The Astrophysical Journal, 2023
Jeans escape or hydrodynamic escape is believed to dominate atmospheric loss for hot Jupiters. However, nonthermal mechanisms likely contribute substantially on hydrogen-rich “super-Earths” with relatively cold and extended atmospheres.
Hao Gu, Xiaoshu Wu, Xu Huang, Jianheng Guo, Jun Cui   +4 more
doaj   +1 more source

Disequilibrium Chemistry in Exoplanet Atmospheres Observed with the Hubble Space Telescope

Astronomical Journal, 2021
Literature on the theory of exoplanet atmospheric disequilibrium chemistry is rich, although its observational counterpart has yet to emerge beyond the hints provided by a few targets in dedicated studies. We report results from an uniform data reduction
Gaël M. Roudier, Mark G. Swain, Murthy S. Gudipati, Robert A. West, Raissa Estrela, Robert T. Zellem   +5 more
openalex   +2 more sources

Retrieving C and O Abundance of HR 8799 c by Combining High- and Low-resolution Data

The Astronomical Journal, 2022
The formation and evolution pathway for the directly imaged multiplanetary system HR 8799 remains mysterious. Accurate constraints on the chemical composition of the planetary atmosphere(s) are key to solving the mystery.
Ji Wang, Jason J. Wang, Jean-Baptiste Ruffio, Geoffrey A. Blake, Dimitri Mawet, Ashley Baker, Randall Bartos, Charlotte Z. Bond, Benjamin Calvin, Sylvain Cetre, Jacques-Robert Delorme, Greg Doppmann, Daniel Echeverri, Luke Finnerty, Michael P. Fitzgerald, Nemanja Jovanovic, Ronald Lopez, Emily C. Martin, Evan Morris, Jacklyn Pezzato, Sam Ragland, Garreth Ruane, Ben Sappey, Tobias Schofield, Andrew Skemer, Taylor Venenciano, J. Kent Wallace, Peter Wizinowich, Jerry W. Xuan, Marta L. Bryan, Arpita Roy, Nicole L. Wallack   +31 more
doaj   +1 more source

Chemical modeling of exoplanet atmospheres [PDF]

Experimental Astronomy, 2014
The past twenty years have revealed the diversity of planets that exist in the Universe. It turned out that most of exoplanets are different from the planets of our Solar System and thus, everything about them needs to be explored. Thanks to current observational technologies, we are able to determine some information about the atmospheric composition,
Marcelino Agúndez, Marcelino Agúndez, Olivia Venot   +2 more
openaire   +5 more sources

Exoplanet secondary atmosphere loss and revival [PDF]

Proceedings of the National Academy of Sciences, 2020
SignificanceEarth and Venus have significant atmospheres, but Mercury does not. Thousands of exoplanets are known, but we know almost nothing about rocky exoplanet atmospheres. Many rocky exoplanets were formed by a sub-Neptune-to-super-Earth conversion process during which planets lose most of their H2-rich (primary) atmospheres and are reduced in ...
Edwin S. Kite, Megan Barnett
openalex   +5 more sources

Atmospheric Seasonality as an Exoplanet Biosignature [PDF]

The Astrophysical Journal Letters, 2018
Abstract Current investigations of exoplanet biosignatures have focused on static evidence of life, such as the presence of biogenic gases like O2 or CH4. However, the expected diversity of terrestrial planet atmospheres and the likelihood of both “false positives” and “false negatives” for conventional biosignatures motivate exploration
Victoria S. Meadows, Victoria S. Meadows, Andy Ridgwell, Andy Ridgwell, Stephanie L. Olson, Stephanie L. Olson, Stephen R. Kane, Stephen R. Kane, Christopher T. Reinhard, Christopher T. Reinhard, Edward W. Schwieterman, Timothy W. Lyons, Timothy W. Lyons   +12 more
openaire   +6 more sources

A JWST NIRSpec Phase Curve for WASP-121b: Dayside Emission Strongest Eastward of the Substellar Point and Nightside Conditions Conducive to Cloud Formation

The Astrophysical Journal Letters, 2023
We present the first exoplanet phase-curve measurement made with the JWST NIRSpec instrument, highlighting the exceptional stability of this newly commissioned observatory for exoplanet climate studies.
Thomas Mikal-Evans, David K. Sing, Jiayin Dong, Daniel Foreman-Mackey, Tiffany Kataria, Joanna K. Barstow, Jayesh M. Goyal, Nikole K. Lewis, Joshua D. Lothringer, Nathan J. Mayne, Hannah R. Wakeford, Duncan A. Christie, Zafar Rustamkulov   +12 more
doaj   +1 more source

The Runaway Greenhouse on Sub-Neptune Waterworlds

The Astrophysical Journal, 2023
The implications of the water vapor runaway greenhouse phenomenon for water-rich sub-Neptunes are developed. In particular, the nature of the postrunaway equilibration process for planets that have an extremely high water inventory is addressed. Crossing
Raymond T. Pierrehumbert
doaj   +1 more source

Haze Formation in Warm H₂-rich Exoplanet Atmospheres [PDF]

The Planetary Science Journal, 2020
New observing capabilities coming online over the next few years will provide opportunities for characterization of exoplanet atmospheres. However, clouds/hazes could be present in the atmospheres of many exoplanets, muting the amplitude of spectral ...
Chao He, Sarah M. Hörst, Nikole K. Lewis, Xinting Yu, Julianne I. Moses, Patricia McGuiggan, Mark S. Marley, Eliza M.-R. Kempton, Caroline Morley, Jeff A. Valenti, V. Vuitton   +10 more
openalex   +2 more sources