Results 41 to 50 of about 94,271 (166)

JWST Transmission Spectroscopy of HD 209458b: A Supersolar Metallicity, a Very Low C/O, and No Evidence of CH4, HCN, or C2H2

The Astrophysical Journal Letters
We present the transmission spectrum of the original transiting hot Jupiter HD 209458b from 2.3 to 5.1 μ m as observed with the NIRCam instrument on the James Webb Space Telescope (JWST). Previous studies of HD 209458b’s atmosphere have given conflicting
Qiao Xue, Jacob L. Bean, Michael Zhang, Luis Welbanks, Jonathan Lunine, Prune August   +5 more
doaj   +1 more source

Fleeting but Not Forgotten: The Imprint of Escaping Hydrogen Atmospheres on Super-Earth Interiors

The Astrophysical Journal
Small, close-in exoplanets are divided into two subpopulations: super-Earths and sub-Neptunes. Most super-Earths are thought to have lost their primordially accreted hydrogen-dominated atmospheres via thermally driven winds.
James G. Rogers, Hilke E. Schlichting, Edward D. Young   +2 more
doaj   +1 more source

Constraining Atmospheric Composition from the Outflow: Helium Observations Reveal the Fundamental Properties of Two Planets Straddling the Radius Gap

The Astronomical Journal
TOI-836 is a ∼2–3 Gyr K dwarf with an inner super Earth ( R  = 1.7 R _⊕ , P = 3.8 days) and an outer mini-Neptune ( R  = 2.6 R _⊕ , P = 8.6 days). JWST/NIRSpec 2.8–5.2 μ m transmission spectra are flat for both planets.
Michael Zhang, Jacob L. Bean, David Wilson, Girish Duvvuri, Christian Schneider, Heather A. Knutson, Fei Dai, Karen A. Collins, Cristilyn N. Watkins, Richard P. Schwarz, Khalid Barkaoui, Avi Shporer, Keith Horne, Ramotholo Sefako, Felipe Murgas, Enric Palle   +15 more
doaj   +1 more source

The Roasting Marshmallows Program with IGRINS on Gemini South I: Composition and Climate of the Ultrahot Jupiter WASP-18 b

The Astronomical Journal, 2023
We present high-resolution dayside thermal emission observations of the exoplanet WASP-18 b using IGRINS on Gemini South. We remove stellar and telluric signatures using standard algorithms, and we extract the planet signal via cross-correlation with ...
Matteo Brogi, Vanessa Emeka-Okafor, Michael R. Line, Siddharth Gandhi, Lorenzo Pino, Eliza M.-R. Kempton, Emily Rauscher, Vivien Parmentier, Jacob L. Bean, Gregory N. Mace, Nicolas B. Cowan, Evgenya Shkolnik, Joost P. Wardenier, Megan Mansfield, Luis Welbanks, Peter Smith, Jonathan J. Fortney, Jayne L. Birkby, Joseph A. Zalesky, Lisa Dang, Jennifer Patience, Jean-Michel Désert   +21 more
doaj   +1 more source

Origin and Extent of the Opacity Challenge for Atmospheric Retrievals of WASP-39 b

The Astrophysical Journal Letters, 2023
As the James Webb Space Telescope (JWST) came online last summer, we entered a new era of astronomy. This new era is supported by data products of unprecedented information content that require novel reduction and analysis techniques.
Prajwal Niraula, Julien de Wit, Iouli E. Gordon, Robert J. Hargreaves, Clara Sousa-Silva   +4 more
doaj   +1 more source

Patchy Forsterite Clouds in the Atmospheres of Two Highly Variable Exoplanet Analogs

The Astrophysical Journal, 2023
We present an atmospheric retrieval analysis of a pair of highly variable, ∼200 Myr old, early T type planetary-mass exoplanet analogs SIMP J01365662+0933473 and 2MASS J21392676+0220226 using the Brewster retrieval framework.
Johanna M. Vos, Ben Burningham, Jacqueline K. Faherty, Sherelyn Alejandro, Eileen Gonzales, Emily Calamari, Daniella Bardalez Gagliuffi, Channon Visscher, Xianyu Tan, Caroline V. Morley, Mark Marley, Marina E. Gemma, Niall Whiteford, Josefine Gaarn, Grace Park   +14 more
doaj   +1 more source

Properties of Sub-Neptune Atmospheres: TOI-270 System [PDF]

, 2020
We investigate the potential for the James Webb Space Telescope (JWST) to detect and characterize the atmospheres of the sub-Neptunian exoplanets in the TOI-270 system. Sub-Neptunes are considered more likely to be water worlds than gas dwarfs. We model their atmospheres using three atmospheric compositions - two examples of hydrogen-dominated ...
arxiv   +1 more source

Clouds and Hazes in GJ 1214 b’s Metal-rich Atmosphere

The Astronomical Journal
The sub-Neptune GJ 1214 b has an infamously flat transmission spectrum, likely due to thick aerosols in its atmosphere. A recent JWST/MIRI spectroscopic phase curve of GJ 1214 b added to this picture, suggesting a highly reflective and metal-rich ...
Isaac Malsky, Emily Rauscher, Kevin Stevenson, Arjun B. Savel, Maria E. Steinrueck, Peter Gao, Eliza M.-R. Kempton, Michael T. Roman, Jacob L. Bean, Michael Zhang, Vivien Parmentier, Anjali A. A. Piette, Tiffany Kataria   +12 more
doaj   +1 more source

The effect of a small amount of H and H2O in magma-ocean rocky-exoplanets : atmospheric composition and escape [PDF]

, 2023
S. Charnoz, Aurélien Falco, Paolo A. Sossi, Pascal Tremblin, Pierre-Olivier Lagage, Razvan Caracas   +5 more
openalex   +1 more source

Transmission Spectroscopy of the Lowest-density Gas Giant: Metals and a Potential Extended Outflow in HAT-P-67b

The Astronomical Journal, 2023
Extremely low-density exoplanets are tantalizing targets for atmospheric characterization because of their promisingly large signals in transmission spectroscopy.
Aaron Bello-Arufe, Heather A. Knutson, João M. Mendonça, Michael M. Zhang, Samuel H. C. Cabot, Alexander D. Rathcke, Ana Ulla, Shreyas Vissapragada, Lars A. Buchhave   +8 more
doaj   +1 more source