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arXiv · 2606.17272

Pre-nova Observations of T CrB: A view from the CHARA Array

Ryan Norris·Narsireddy Anugu·Thomas Gaudin·Magdalena Otulakowska-Hypka·Fabian Kaczmarek·Cameron Caruso·Cody Gustafson·Andrew Kotowski·Rebecca Proni·Nirupam Roy·Fabien Baron·Dipankar P. K Banerjee·Dana K. Baylis-Aguirre·Michelle J. Creech-Eakman·Justin Linford·Alexandre Gallenne·Joanna Mikołajewska·John D. Monnier·Denis Mourard·Ulisse Munari·Nicolas Nardetto·Rachael M. Roettenbacher·Jennifer L Sokoloski·Montana Williams·C. E. Woodward·Stefan Kraus·Jean-Baptiste Le Bouquin·Sorabh Chhabra·Isabelle Codron·Jacob Ennis·Tyler Gardner·Mayra Gutierrez·Noura Ibrahim·Cyprien Lanthermann·Benjamin R. Setterholm·Christopher D. Farrington·Olli Majoinen·Norm Vargas·Douglas R. Gies·Gail H. Schaefer·Theo ten Brummelaar
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Abstract

T CrB is a symbiotic recurrent nova consisting of a red giant and white dwarf with recent eruptions in 1866 and 1946 and an anticipated eruption in the mid 2020s. We report CHARA Array observations obtained with MIRC-X (H -band) and MYSTIC (K-band) in 2022-2025. We fit limb darkened disk models constrained with literature limb darkening coefficients to the squared visibilities as only the first visibility lobe is sampled. The average limb darkened diameter of the star across these epochs is $0.70\pm0.04$ mas in H-band and $0.72\pm0.07$ mas in K-band. Adopting a distance of $914^{+24}_{-22}$ pc, the stellar radius is $69\pm5~R_{\odot}$ in H-band and $71\pm8~R_{\odot}$ in K-band. This is consistent with filling a Roche lobe volume radius of $71~R_{\odot}$ inferred from published orbital solutions. These measurements provide a pre-eruption angular diameter and support a Roche lobe filling donor.

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Ryan Norris, Narsireddy Anugu, Thomas Gaudin, Magdalena Otulakowska-Hypka, Fabian Kaczmarek, Cameron Caruso, Cody Gustafson, Andrew Kotowski, Rebecca Proni, Nirupam Roy, Fabien Baron, Dipankar P. K Banerjee, Dana K. Baylis-Aguirre, Michelle J. Creech-Eakman, Justin Linford, Alexandre Gallenne, Joanna Mikołajewska, John D. Monnier, Denis Mourard, Ulisse Munari, Nicolas Nardetto, Rachael M. Roettenbacher, Jennifer L Sokoloski, Montana Williams, C. E. Woodward, Stefan Kraus, Jean-Baptiste Le Bouquin, Sorabh Chhabra, Isabelle Codron, Jacob Ennis, Tyler Gardner, Mayra Gutierrez, Noura Ibrahim, Cyprien Lanthermann, Benjamin R. Setterholm, Christopher D. Farrington, Olli Majoinen, Norm Vargas, Douglas R. Gies, Gail H. Schaefer, Theo ten Brummelaar. 2026-06-15. Pre-nova Observations of T CrB: A view from the CHARA Array. https://doi.org/10.3847/2041-8213%2Fae71d0

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