{"paper":{"title":"ASASSN-14ko is a Periodic Nuclear Transient in ESO 253-G003","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Adam C. Schneider, A.N. Heinze, Anna V. Payne, Benjamin J. Shappee, Berto Monard, Christopher S. Kochanek, Dirk Grupe, Heather Flewelling, Henry Weiland, Jack M. M. Neustadt, James D. Armstrong, Jason T. Hinkle, John L. Tonry, Jose L. Prieto, Joseph Brimacombe, Katie Auchettl, K. Z. Stanek, Larry Denneau, Laura A. Lopez, Michael A. Tucker, Michael M. Fausnaugh, Patrick J. Vallely, Paulo Cacella, Robert Cornect, Scott S. Sheppard, Thomas W.-S. Holoien, Todd A. Thompson","submitted_at":"2020-09-07T18:00:01Z","abstract_excerpt":"We present the discovery that ASASSN-14ko is a periodically flaring AGN at the center of the galaxy ESO 253-G003. At the time of its discovery by the All-Sky Automated Survey for Supernovae (ASAS-SN), it was classified as a supernova close to the nucleus. The subsequent six years of V- and g-band ASAS-SN observations reveal that ASASSN-14ko has nuclear flares occurring at regular intervals. The seventeen observed outbursts show evidence of a decreasing period over time, with a mean period of $P_0 = 114.2 \\pm 0.4$ days and a period derivative of $\\dot{P} = -0.0017\\pm0.0003$. The most recent out"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2009.03321","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2009.03321/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"}