{"paper":{"title":"Seeing the Outer Edge of the Infant Type Ia Supernova 2024epr in the Optical and Near Infrared","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.HE","authors_text":"A. Do, A. Gagliano, A. R. Wasserman, A. Syncatto, B. J. Shappee, C. Ashall, C.-C. Lin, C. R. Angus, D. A. Coulter, D. D. Desai, D. O. Jones, E. A. Magnier, J. Shi, J. T. Hinkle, K. Auchettl, K. C. Chambers, K.C. Patra, K. Taggart, K. W. Davis, M. A. Tucker, M. E. Huber, M. Kong, P. Chen, P. Minguez, R. J. Foley, R. S. Post, S. A. Severson, S. K. Yadavalli, S. Romagnoli, T. B. Lowe, T. de Boer, W. B. Hoogendam, Y.-C. Pan","submitted_at":"2025-02-24T19:00:01Z","abstract_excerpt":"We present optical-to-near-infrared (NIR) photometry and spectroscopy of the Type Ia supernova (SN Ia) 2024epr, including NIR spectra observed within two days of first light. The early-time optical spectra show strong, high-velocity Ca and Si features near rarely-observed velocities at $\\sim$0.1$c$, and the NIR spectra show a C I \"knee.\" Despite early-time, high-velocity features, SN 2024epr evolves into a normal SN Ia, albeit with stronger peak-light Ca absorption than other SNe Ia with the same light curve shape. Although we infer a normal decline rate, $\\Delta m_{15}(B)=1.09\\pm0.12$ mag, fr"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2502.17556","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2502.17556/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}