Results 1 to 10 of about 2,900,879 (209)

A Metal-poor Atmosphere with a Hot Interior for a Young Sub-Neptune Progenitor: JWST/NIRSpec Transmission Spectrum of V1298 Tau b

The Astronomical Journal
We present the JWST/NIRSpec G395H transmission spectrum of the young (10–30 Myr) transiting planet V1298 Tau b (9.85 ± 0.35 R _⊕ , T _eq  = 670 K). Combined Hubble Space Telescope and JWST observations reveal a haze-free, H/He-dominated atmosphere with a
Saugata Barat, Jean-Michel Désert, Sagnick Mukherjee, Jayesh M. Goyal, Qiao Xue, Yui Kawashima, Allona Vazan, William Misener, Hilke E. Schlichting, Jonathan J. Fortney, Jacob L. Bean, Swaroop Avarsekar, Gregory W. Henry, Robin Baeyens, Michael R. Line, John H. Livingston, Trevor David, Erik A. Petigura, James T. Sikora, Hinna Shivkumar, Adina D. Feinstein, Antonija Oklopčić   +21 more
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Bistability, Oscillations, and Multistability on Hycean Planets

The Astrophysical Journal
Hycean planets are hypothetical exoplanets characterized by H _2 O oceans and H _2 -rich atmospheres. These planets are high-priority targets for biosignature searches, as they combine abundant surface liquid water with easy-to-characterize H _2 -rich ...
Yichen Gao, Daniel D. B. Koll, Feng Ding
doaj   +1 more source

The JWST Rocky Worlds DDT Program Reveals GJ 3929b to Likely Be a Bare Rock

The Astrophysical Journal Letters
We report first results from the JWST Rocky Worlds Director’s Discretionary Time program. Two secondary eclipses of the terrestrial exoplanet GJ 3929b were recently observed using MIRI photometric imaging at 15 μ m.
Qiao Xue, Michael Zhang, Brandon Park Coy, Madison Brady, Xuan Ji, Jacob L. Bean, Michael Radica, Andreas Seifahrt, Julian Stürmer, Rafael Luque, Ritvik Basant, Nina Brown, Tanya Das, David Kasper, Caroline Piaulet-Ghorayeb, Eliza M.-R. Kempton, Edwin Kite   +16 more
doaj   +1 more source

Helium-poor Winds Do Not Require Helium-poor Planets

The Astrophysical Journal
Observations of the metastable He i 10830 Å triplet have revealed escaping exoplanet atmospheres whose inferred helium abundances range from nearly nebular compositions to strongly helium-depleted winds. Such depletion is commonly interpreted as evidence
Leonardos Gkouvelis, Francisco J. Pozuelos   +1 more
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Sulfur Dioxide and Other Molecular Species in the Atmosphere of the Sub-Neptune GJ 3470 b

The Astrophysical Journal Letters
We report observations of the atmospheric transmission spectrum of the sub-Neptune exoplanet GJ 3470 b taken using the Near-Infrared Camera on JWST.
Thomas G. Beatty, Luis Welbanks, Everett Schlawin, Taylor J. Bell, Michael R. Line, Matthew Murphy, Isaac Edelman, Thomas P. Greene, Jonathan J. Fortney, Gregory W. Henry, Sagnick Mukherjee, Kazumasa Ohno, Vivien Parmentier, Emily Rauscher, Lindsey S. Wiser, Anastasia Triantafillides   +15 more
doaj   +1 more source

Irradiated Atmospheres. IV. Effect of Mixing Heat Flux on Chemistry

The Astrophysical Journal
Vertical mixing disrupts the thermochemical equilibrium and introduces additional heat flux that alters exoplanetary atmospheric temperatures. We investigate how this mixing-induced heat flux affects atmospheric chemistry.
Zhen-Tai Zhang, Wei Zhong, Wei Wang, Jianheng Guo, Xianyu Tan, Bo Ma, Ruyi Wei, Cong Yu   +7 more
doaj   +1 more source

Unraveling the Mystery of the Peculiar and Young Hot Jupiter CoRoT-2b. I. H2O and CO Detection from Dayside Observations with Gemini-S/IGRINS

The Astronomical Journal
We present ground-based high-resolution spectroscopic pre-eclipse observations of the hot Jupiter CoRoT-2b obtained with the IGRINS spectrograph on Gemini South.
Ying Shu, Lisa Dang, Antoine Darveau-Bernier, Aurora Kesseli, Luc Bazinet, Justin Lipper, Stefan Pelletier, Romain Allart, Nicolas B. Cowan, David Lafreniére, Emily Rauscher, Alejandro Sánchez-López, Björn Benneke, Anne Boucher, René Doyon   +14 more
doaj   +1 more source

The Metallicity and Carbon-to-oxygen Ratio of the Ultrahot Jupiter WASP-76b from Gemini-S/IGRINS

The Astronomical Journal
Measurements of the carbon-to-oxygen (C/O) ratios of exoplanet atmospheres can reveal details about their formation and evolution. Recently, high-resolution cross-correlation analysis has emerged as a method of precisely constraining the C/O ratios of ...
Megan Weiner Mansfield, Michael R. Line, Joost P. Wardenier, Matteo Brogi, Jacob L. Bean, Hayley Beltz, Peter Smith, Joseph A. Zalesky, Natasha Batalha, Eliza M.-R. Kempton, Benjamin T. Montet, James E. Owen, Peter Plavchan, Emily Rauscher   +13 more
doaj   +1 more source

Early Accretion of Large Amounts of Solids for Directly Imaged Exoplanets

The Astrophysical Journal
As the number of planetary-mass objects (PMOs; ⪅13 M _Jupiter ) at wider separation (⪆10 au) grows, there is emerging evidence that they form differently from their higher-mass brown dwarf counterparts.
Ji Wang
doaj   +1 more source

Distinguishing Oceans of Water from Magma on Mini-Neptune K2-18b

The Astrophysical Journal Letters
Mildly irradiated mini-Neptunes have densities potentially consistent with them hosting substantial liquid-water oceans (“Hycean” planets). The presence of CO _2 and simultaneous absence of ammonia (NH _3 ) in their atmospheres has been proposed as a ...
Oliver Shorttle, Sean Jordan, Harrison Nicholls, Tim Lichtenberg, Dan J. Bower   +4 more
doaj   +1 more source