{"paper":{"title":"Optical flux and spectral variability of BL Lacertae during its historical high outburst in 2020","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Alok C. Gupta, Anton A. Strigachev, Hongyan Zhou, Junhui Fan, Lang Cui, Minfeng Gu, Nibedita Kalita, Peng Jiang, Rumen S. Bachev, Xiang Pan, Yosuke Mizuno, Yuhai Yuan","submitted_at":"2022-12-08T10:36:16Z","abstract_excerpt":"BL Lacertae had undergone a series of historical high flux activity over a year, from August 2020 in the optical to VHE $\\gamma$-rays. In this paper, we report on optical flux and spectral variability of the first historical maxima outburst event during October-November in g, r and i bands with the 1.26m telescope at Xinglong observatory, China. We detected significant intranight variations with amplitude rising up to $\\sim 30$%, when the fastest variability timescale is found to be a few tens of minutes, giving an emitting region size of the order $10^{-3}$ pc, which corresponds to $\\sim 100$"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2212.04181","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/2212.04181/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"}