{"paper":{"title":"Periodic Variability of the Barium Central Star of the Planetary Nebula Abell 70","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"2), (2) Space Telescope Science Institute), Howard E. Bond (1, Penn State, Robin Ciardullo (1) ((1) Dept. of Astronomy & Astrophysics","submitted_at":"2018-08-03T16:36:20Z","abstract_excerpt":"Abell 70 is a planetary nebula (PN) whose nucleus at optical wavelengths is a G8 star with enhanced carbon and s-process abundances--a \"barium star.\" The cool star is a binary companion of the true, hot central star. In several other members of this rare class, the cool star is known to rotate with a period of only a few days. This is attributed to a spin-up that occurred due to accretion from the wind of the central star during its post-AGB PN ejection; this also accounts for the unusual chemical composition of the companion's photosphere. We obtained photometry of the central star of Abell 7"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1808.01251","kind":"arxiv","version":1},"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"}