{"paper":{"title":"The early discovery of SN 2017ahn: signatures of persistent interaction in a fast declining Type II supernova","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.HE","authors_text":"A. Rau, C. McCully, D. A. Howell, D. E. Reichart, D. Hiramatsu, D. J. Sand, E. Y. Hsiao, F. F\\\"orster, G. Hosseinzadeh, H. Kuncarayakti, J. Burke, J. D. Lyman, J. Haislip, J. H. Groh, J. Strader, K. A. Bostroem, L. Galbany, L. Tartaglia, M. M. Phillips, M. Shahbandeh, P. J. Brown, S. Davis, S. D. Wyatt, S. Valenti, S. W. Jha, S. Yang, T. -W. Chen, V. Kouprianov","submitted_at":"2020-08-14T18:00:03Z","abstract_excerpt":"We present high-cadence, comprehensive data on the nearby ($D\\simeq33\\,\\rm{Mpc}$) Type II SN 2017ahn, discovered within $\\sim$1 day of explosion, from the very early phases after explosion to the nebular phase. The observables of SN 2017ahn show a significant evolution over the $\\simeq470\\,\\rm{d}$ of our follow-up campaign, first showing prominent, narrow Balmer lines and other high-ionization features purely in emission (i.e. flash spectroscopy features), which progressively fade and lead to a spectroscopic evolution similar to that of more canonical Type II supernovae. Over the same period, "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2008.06515","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/2008.06515/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"}