Results 21 to 30 of about 53,484 (152)
Detection of an Atmosphere on a Rocky Exoplanet [PDF]
The Astronomical Journal, 2021 Abstract We report the detection of an atmosphere on a rocky exoplanet, GJ 1132 b, which is similar to Earth in terms of size and density. The atmospheric transmission spectrum was detected using Hubble WFC3 measurements and shows spectral signatures of aerosol scattering, HCN, and CH4 in a low mean molecular weight atmosphere.
Mark R. Swain +9 more
openaire +4 more sources
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 +4 more
doaj +1 more source
Helium in the eroding atmosphere of an exoplanet [PDF]
Nature, 2018 Helium is the second-most abundant element in the Universe after hydrogen and is one of the main constituents of gas-giant planets in our Solar System. Early theoretical models predicted helium to be among the most readily detectable species in the atmospheres of exoplanets, especially in extended and escaping atmospheres 1 .
Yifan Zhou +23 more
openaire +7 more sources
Exoplanet Atmospheres and Photochemistry [PDF]
Proceedings of the International Astronomical Union, 2006 Over 150 extrasolar planets are known to orbit sun-like stars. A growing number of them (9 to date) are transiting “hot Jupiters” whose physical characteristics can be measured. Atmospheres of two of these planets have already been detected. We summarize the atmosphere detections and useful upper limits, focusing on the MOST albedo upper limit and II ...
Seager, S. +3 more
openaire +4 more sources
The Astrophysical Journal, 2023 The near-infrared transmission spectrum of the warm sub-Neptune exoplanet GJ 1214 b has been observed to be flat and featureless, implying a high metallicity atmosphere with abundant aerosols.
Peter Gao +14 more
doaj +1 more source
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 +12 more
doaj +1 more source
A New Method For Studying Exoplanet Atmospheres Using Planetary Infrared Excess [PDF]
ApJL 898 L35 (2020), 2020 To date, the ability for observers to reveal the composition or thermal structure of an exoplanet's atmosphere has rested on two techniques: high-contrast direct imaging and time-series observations of transiting exoplanets. The former is currently limited to characterizing young, massive objects while the latter requires near 90 degree orbital ...
arxiv +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
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 +31 more
doaj +1 more source
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 +12 more
openaire +6 more sources