The Identification of CS2 and Evidence for Carbon-Sulfur Chemical Coupling in a Warm Giant Exoplanet Atmosphere

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Triantafillides, Anastasia, Beatty, Thomas G., Nixon, Matthew C., Bell, Taylor J., Schlawin, Everett, Welbanks, Luis, Greene, Thomas P., Soares-Furtado, Melinda, Line, Jonathan J. Fortney Michael R., Mehta, Nishil, Mukherjee, Sagnick, Murphy, Matthew M., Ohno, Kazumasa, Parmentier, Vivien, Rotman, Yoav, Wiser, Lindsey S.
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917412766482432
author Triantafillides, Anastasia
Beatty, Thomas G.
Nixon, Matthew C.
Bell, Taylor J.
Schlawin, Everett
Welbanks, Luis
Greene, Thomas P.
Soares-Furtado, Melinda
Line, Jonathan J. Fortney Michael R.
Mehta, Nishil
Mukherjee, Sagnick
Murphy, Matthew M.
Ohno, Kazumasa
Parmentier, Vivien
Rotman, Yoav
Wiser, Lindsey S.
author_facet Triantafillides, Anastasia
Beatty, Thomas G.
Nixon, Matthew C.
Bell, Taylor J.
Schlawin, Everett
Welbanks, Luis
Greene, Thomas P.
Soares-Furtado, Melinda
Line, Jonathan J. Fortney Michael R.
Mehta, Nishil
Mukherjee, Sagnick
Murphy, Matthew M.
Ohno, Kazumasa
Parmentier, Vivien
Rotman, Yoav
Wiser, Lindsey S.
contents Transmission spectroscopy with the James Webb Space Telescope (JWST) is revealing growing chemical complexity in giant exoplanet atmospheres. Of particular interest is sulfur, which had essentially no observational constraints before JWST. Recent work has shown that a planet's atmospheric sulfur content traces its refractory budget and is therefore a sensitive indicator of formation pathways. But despite the growing library of JWST data, the sulfur inventory of giant exoplanets remains poorly constrained: sulfur-bearing species are governed by disequilibrium chemistry and by kinetic networks that are still being revised. Here we present a transmission spectrum of the warm giant planet WASP-80 b obtained with JWST/NIRCam and MIRI over 2.4 $μ$m--10$μ$m in three transits. We find evidence for H$_2$O, CH$_4$, CO$_2$, NH$_3$, and CS$_2$ in the atmosphere and place upper limits on CO and SO$_2$. Our atmospheric retrievals yield $\log_{10}\mathrm{X}_{\mathrm{CS_2}} = -2.25^{+0.33}_{-0.32}$. This CS$_2$ abundance is substantially higher than predicted by earlier sulfur-chemistry schemes for H$_2$-rich atmospheres in WASP-80 b's temperature range, but is consistent with recent chemically validated networks that include efficient carbon-sulfur coupling through CH$_2$S. These results identify CS$_2$ as an observable tracer of sulfur disequilibrium chemistry and provide observational support for theoretically predicted carbon-sulfur chemical coupling in giant exoplanet atmospheres.
format Preprint
id arxiv_https___arxiv_org_abs_2604_13168
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The Identification of CS2 and Evidence for Carbon-Sulfur Chemical Coupling in a Warm Giant Exoplanet Atmosphere
Triantafillides, Anastasia
Beatty, Thomas G.
Nixon, Matthew C.
Bell, Taylor J.
Schlawin, Everett
Welbanks, Luis
Greene, Thomas P.
Soares-Furtado, Melinda
Line, Jonathan J. Fortney Michael R.
Mehta, Nishil
Mukherjee, Sagnick
Murphy, Matthew M.
Ohno, Kazumasa
Parmentier, Vivien
Rotman, Yoav
Wiser, Lindsey S.
Earth and Planetary Astrophysics
Transmission spectroscopy with the James Webb Space Telescope (JWST) is revealing growing chemical complexity in giant exoplanet atmospheres. Of particular interest is sulfur, which had essentially no observational constraints before JWST. Recent work has shown that a planet's atmospheric sulfur content traces its refractory budget and is therefore a sensitive indicator of formation pathways. But despite the growing library of JWST data, the sulfur inventory of giant exoplanets remains poorly constrained: sulfur-bearing species are governed by disequilibrium chemistry and by kinetic networks that are still being revised. Here we present a transmission spectrum of the warm giant planet WASP-80 b obtained with JWST/NIRCam and MIRI over 2.4 $μ$m--10$μ$m in three transits. We find evidence for H$_2$O, CH$_4$, CO$_2$, NH$_3$, and CS$_2$ in the atmosphere and place upper limits on CO and SO$_2$. Our atmospheric retrievals yield $\log_{10}\mathrm{X}_{\mathrm{CS_2}} = -2.25^{+0.33}_{-0.32}$. This CS$_2$ abundance is substantially higher than predicted by earlier sulfur-chemistry schemes for H$_2$-rich atmospheres in WASP-80 b's temperature range, but is consistent with recent chemically validated networks that include efficient carbon-sulfur coupling through CH$_2$S. These results identify CS$_2$ as an observable tracer of sulfur disequilibrium chemistry and provide observational support for theoretically predicted carbon-sulfur chemical coupling in giant exoplanet atmospheres.
title The Identification of CS2 and Evidence for Carbon-Sulfur Chemical Coupling in a Warm Giant Exoplanet Atmosphere
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2604.13168