SPIRITS 19q: Dust Production by a Subsolar-metallicity Carbon-rich Wolf-Rayet Star in NGC 2403

October 2026 • 2026PASP..138j4207R

Authors • Rose, Sam • Lau, Ryan M. • Jencson, Jacob E. • Kasliwal, Mansi M. • Sander, Andreas A. C. • Bond, Howard E. • Corcoran, Michael F. • De, Kishalay • Endo, Izumi • Hankins, Matthew J. • Jones, Olivia C. • Karambelkar, Viraj R. • Lamberts, Astrid • Madura, Thomas • Moffat, Anthony F. J. • Morris, Patrick W. • Onaka, Takashi • Ressler, Michael E. • Richardson, Noel D. • Russell, Christopher M. P. • Sakon, Itsuki • Sanchez-Bermudez, J. • Weigelt, Gerd • Williams, Peredur M.

Abstract • We present JWST/NIRSpec IFU observations of SPIRITS 19q, the highly dust-producing carbon-rich (WC) binary candidate located in a subsolar-metallicity region of the nearby spiral galaxy NGC 2403. The observations, taken in April of 2024, confirm the association of a dusty outburst observed in 2019 by the Spitzer Space Telescope with an early-type WC star. Using models from the Potsdam Wolf--Rayet (PoWR) LMC model grid we find that the WC star of SPIRITS 19q likely has an especially high mass-loss rate (≳10^-4 M_⊙ yr^-1). From the flux peak of the IR transient as measured by Spitzer/InfraRed Array Camera (IRAC) as well as constraints on dust composition and size from the JWST spectrum, we estimate a total dust mass formed in the outburst of 6.6 ± 0.4 × 10^-6 M_⊙. Assuming a minimum orbital period of 12 yr, this corresponds to a period-averaged dust production rate of ≲5.5 × 10^-7 M_⊙ yr^-1. These observations suggest that even a single WC system can contribute to the dust budget at subsolar metallicities, and that such systems are an important source of carbonaceous dust grains in the early universe.

Links

• PDF https://iopscience.iop.org/article/10.1088/1538-3873/ae9a01/pdf
• PREPRINT http://arxiv.org/abs/2609.00477
• ELECTR https://doi.org/10.1088/1538-3873/ae9a01