{"paper":{"title":"Superluminous supernova 2015bn in the nebular phase: evidence for the engine-powered explosion of a stripped massive star","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.HE","authors_text":"A. Gal-Yam, A. Jerkstrand, C. Inserra, C. McCully, D. A. Howell, D. Milisavljevic, D. R. Young, E. A. Magnier, E. Berger, E. Kankare, G. Hosseinzadeh, I. Arcavi, K. C. Chambers, K. Maguire, K. W. Smith, M. Nicholl, O. Yaron, P. A. Mazzali, P. Challis, P. K. Blanchard, P. .S. Cowperthwaite, R. Chornock, R. J. Wainscoat, R. Margutti, S. J. Smartt, S. Taubenberger, S. Valenti, T.-W. Chen","submitted_at":"2016-08-09T22:20:46Z","abstract_excerpt":"We present nebular-phase imaging and spectroscopy for the hydrogen-poor superluminous supernova SN 2015bn, at redshift z=0.1136, spanning +250-400 d after maximum light. The light curve exhibits a steepening in the decline rate from 1.4 mag/(100 d) to 1.7 mag/(100 d), suggestive of a significant decrease in the opacity. This change is accompanied by a transition from a blue continuum superposed with photospheric absorption lines to a nebular spectrum dominated by emission lines of oxygen, calcium and magnesium. There are no obvious signatures of circumstellar interaction or large nickel mass. "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1608.02995","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"}