Hints of a Sulfur-rich Atmosphere around the 1.6 R ⊕ Super-Earth L98-59 d from JWST NIRspec G395H Transmission Spectroscopy

Amélie Gressier; Néstor Espinoza; Natalie H. Allen; David K. Sing; Agnibha Banerjee; Joanna K. Barstow; Jeff A. Valenti; Nikole K. Lewis; Stephan M. Birkmann; Ryan C. Challener; Elena Manjavacas; Catarina Alves de Oliveira; Nicolas Crouzet; Tracy. L Beck

doi:10.3847/2041-8213/ad73d1

The Astrophysical Journal Letters (Jan 2024)

Hints of a Sulfur-rich Atmosphere around the 1.6 R ⊕ Super-Earth L98-59 d from JWST NIRspec G395H Transmission Spectroscopy

Amélie Gressier,
Néstor Espinoza,
Natalie H. Allen,
David K. Sing,
Agnibha Banerjee,
Joanna K. Barstow,
Jeff A. Valenti,
Nikole K. Lewis,
Stephan M. Birkmann,
Ryan C. Challener,
Elena Manjavacas,
Catarina Alves de Oliveira,
Nicolas Crouzet,
Tracy. L Beck

Affiliations

Amélie Gressier: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Néstor Espinoza: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; William H. Miller III Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA
Natalie H. Allen: ORCiD; William H. Miller III Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA
David K. Sing: ORCiD; Department of Physics and Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA; Department of Earth and Planetary Sciences, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA
Agnibha Banerjee: ORCiD; School of Physical Sciences, The Open University , Milton Keynes, MK7 6AA, UK
Joanna K. Barstow: ORCiD; School of Physical Sciences, The Open University , Milton Keynes, MK7 6AA, UK
Jeff A. Valenti: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Nikole K. Lewis: ORCiD; Department of Astronomy and Carl Sagan Institute, Cornell University , 122 Sciences Drive, Ithaca, NY 14853, USA
Stephan M. Birkmann: ORCiD; European Space Agency, European Space Astronomy Centre , Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain
Ryan C. Challener: ORCiD; Department of Astronomy, Cornell University , 122 Sciences Drive, Ithaca, NY 14853, USA
Elena Manjavacas: ORCiD; Department of Physics and Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA; AURA for the European Space Agency (ESA), ESA Office, Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
Catarina Alves de Oliveira: ORCiD; European Space Agency, European Space Astronomy Centre , Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain
Nicolas Crouzet: ORCiD; Leiden Observatory, Leiden University , P.O. Box 9513, 2300 RA Leiden, The Netherlands
Tracy. L Beck: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA

DOI: https://doi.org/10.3847/2041-8213/ad73d1
Journal volume & issue: Vol. 975, no. 1
p. L10

Abstract

Read online

Detecting atmospheres around planets with a radius below 1.6 R _⊕ , commonly referred to as rocky planets, has proven to be challenging. However, rocky planets orbiting M dwarfs are ideal candidates due to their favorable planet-to-star radius ratio. Here, we present one transit observation of the Super-Earth L98-59 d (1.58 R _⊕ and 2.31 M _⊕ ), at the limit of rocky/gas-rich, using the JWST NIRSpec G395H mode covering the 2.8–5.1 μ m wavelength range. The extracted transit spectrum from a single transit observation deviates from a flat line by 2.6 σ –5.6 σ , depending on the data reduction and retrieval setup. The hints of an atmospheric detection are driven by a large absorption feature between 3.3 and 4.8 μ m. A stellar contamination retrieval analysis rejected the source of this feature as being due to stellar inhomogeneities, making the best fit an atmospheric model including sulfur-bearing species, suggesting that the atmosphere of L98-59 d may not be at equilibrium. This result will need to be confirmed by the analysis of the second NIRSpec G395H visit in addition to the NIRISS SOSS transit observation.

Published in The Astrophysical Journal Letters

ISSN: 2041-8205 (Print); 2041-8213 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/2041-8205

About the journal

Abstract

Keywords