GEMS JWST: A Subsolar Metallicity Atmosphere for Giant Planet TOI-5293 A b Orbiting a Rapidly Changing M Dwarf

The Astrophysical Journal 2026 Open access

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Authors: Shubham Kanodia, Caleb I. Cañas, Jacob Lustig‐Yaeger, Giannina Guzman, Nicole L. Wallack, Simon Müller, Ravit Helled, Knicole D. Colón, Ian Czekala, Megan Delamer, Te Han, Jessica E. Libby-Roberts
+4 more Anjali A. A. Piette, Kevin B. Stevenson, Guðmundur Stefánsson, Johanna K Teske
DOI: 10.3847/1538-4357/ae801f
Cited by: 1
References: 110

Abstract

Abstract The growing sample of giant exoplanets around M dwarf stars (GEMS) helps probe the extremes of giant planet formation. Comparing the properties of this sample with their FGK counterparts can help us understand how planet formation and migration depend on stellar mass. We initiated a large Cycle 2 JWST transmission spectroscopy survey of seven GEMS. Here we present the atmospheric characterization using two JWST transits of TOI-5293 A b, a 0.5 M Jup planet orbiting an early M dwarf with a period of ∼3 days. The two NIRSpec/PRISM transits indicate the planet is eclipsing a rapidly changing (heterogeneous) stellar photosphere. We see that Visit 1 had heterogeneity crossings across the entire transit chord, rendering inferences from it to be unreliable. The Visit 1 spectrum exhibits a downward slope at

Fields of Study & Subjects

Stellar planetary and galactic studies Astrophysics and Star Formation Studies Astronomy and Astrophysical Research

Publication details

Journal / source
The Astrophysical Journal
Publisher
American Astronomical Society
Volume
1006
Issue
2
Pages
119–119
Publication date
20 July 2026
Language
EN