{"paper":{"title":"Superorbital variability in the quiescent black hole X-ray transient A0620-00","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.HE","authors_text":"Daniel Mata S\\'anchez, David M. Russell, Enzo A. Saavedra, Federico Garc\\'ia, Fraser Lewis, Gast\\'on J. Escobar, James F. Steiner, Jorge Casares, Manuel A. P. Torres, Montserrat Armas Padilla, Pablo Rodr\\'iguez-Gil, Roi Alonso, Teo Mu\\~noz-Darias","submitted_at":"2026-07-17T18:00:02Z","abstract_excerpt":"Quiescent black hole low-mass X-ray binaries provide a key setting for probing accretion physics at low luminosities. A0620-00, the archetypal system in this class, has remained in X-ray quiescence for decades and exhibits complex optical variability, yet the long-term behaviour of its accretion flow remains poorly understood. Here, we report an analysis of long-term optical monitoring of A0620-00 from ZTF, LCO, and ATLAS. The full dataset spans nearly two decades, with the ZTF light curve providing the primary $\\sim 2760$-day baseline for the period analysis. We identify a superorbital cycle "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.16397","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/2607.16397/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"}