{"paper":{"title":"Optical Modulation in the X-Ray Binary 4U 1543-624 Revisited","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"A. Tziamtzis (SHAO, China), D. Chakrabarty (Kavli Institute for Astrophysics, D. L. Kaplan (University of Wisconsin-Milwaukee), MIT), Space Research, Z. Wang","submitted_at":"2014-07-08T03:03:47Z","abstract_excerpt":"The X-ray binary 4U 1543$-$624 has been provisionally identified as an ultracompact system with an orbital period of $\\simeq$18~min. We have carried out time-resolved optical imaging of the binary to verify the ultra-short orbital period. Using 140\\,min of high-cadence $r'$-band photometry we recover the previously-seen sinusoidal modulation and determine a period $P=18.20\\pm0.09$\\,min. In addition, we also see a 7.0$\\times 10^{-4}$\\,mag\\,min$^{-1}$ linear decay, likely related to variations in the source's accretion activity. Assuming that the sinusoidal modulation arises from X-ray heating o"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1407.1937","kind":"arxiv","version":2},"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"}