{"paper":{"title":"Supernova 1998S at 14 years Postmortem: Continuing Circumstellar Interaction and Dust Formation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"astro-ph.SR","authors_text":"Jon Mauerhan, Nathan Smith","submitted_at":"2012-04-07T08:01:09Z","abstract_excerpt":"We report late-time spectroscopic observations of the Type IIn SN 1998S, taken 14 years after explosion using the Large Binocular Telescope. The optical spectrum exhibits broad emission features of [O I], [O II], [O III], H-alpha, H-beta, and [Fe II]. The last decade of evolution has exhibited a strengthening of the oxygen transitions, evidence that the late-time emission is powered by increasingly metal-rich SN ejecta crossing the reverse shock. The H-alpha luminosity requires that SN 1998S is still interacting with dense circumstellar material (CSM), probably produced by the strong wind of a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.1610","kind":"arxiv","version":3},"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"}