{"paper":{"title":"Multi-Wavelength Observations of Supernova 2011ei: Time-Dependent Classification of Type IIb and Ib Supernovae and Implications for their Progenitors","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"A. A. M. Gulbis, A. Brunthaler, A. Kniazev, A. MacFadyen, A. M. Soderberg, C. Drescher, C. Fransson, C. Hettlage, D. Buckley, D. Milisavljevic, D. O'Donoghue, D. Reichart, E. Hooper, E. M. Levesque, E. Pian, E. Romero-Colmenero, E. S. Walker, F. Bufano, G. Bock, G. Pignata, J. P. Anderson, J. T. Parrent, K. Ivarsen, K. Nordsieck, L. Chomiuk, M. Bietenholz, M. Wolf, N. Bartel, N. E. Sanders, P. Kotze, P. Marples, P. Mazzali, P. Vaisanen, R. Fesen, R. Margutti, S. Benetti, S. Chakraborti, S. Crawford, S. Parker, S. Potter, T.-O. Husser, T. Pickering","submitted_at":"2012-07-09T20:00:02Z","abstract_excerpt":"We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within 1 day of explosion and span several months afterward. Early optical spectra exhibit broad, Type II-like hydrogen Balmer profiles that subside rapidly and are replaced by Type Ib-like He-rich features on the timescale of one week. High-cadence monitoring of this transition suggests that absorption attributable to a high velocity (> 12,000 km/s) H-rich shell is not rare in Type "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.2152","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":""},"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"}