{"paper":{"title":"Deep $z$-band observations of the coolest Y dwarf","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"Amelia Bayo, Beth A. Biller, Derek Kopon, Elena Manjavacas, Esther Buenzli, Ian J. M. Crossfield, Joshua E. Schlieder, Niall R. Deacon, Taisiya G. Kopytova, Wolfgang Brandner","submitted_at":"2014-10-21T13:30:47Z","abstract_excerpt":"WISE J085510.83-071442.5 (hereafter, WISE 0855-07) is the coolest Y dwarf known to date and is located at a distance of 2.31$\\pm 0.08$ pc, giving it the fourth largest parallax of any known star or brown dwarf system. We report deep $z$-band observations of WISE 0855-07 using FORS2 on UT1/VLT. We do not detect any counterpart to WISE 0855-07 in our $z$-band images and estimate a brightness upper limit of AB mag $>$ 24.8 ($F_{\\nu}$ $<$ 0.45 $\\mu$Jy) at 910 $\\pm$ 65 nm with $3\\sigma$-confidence. We combine our z-band upper limit with previous near- and mid-infrared photometry to place constraint"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1410.5649","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"}