{"paper":{"title":"Large Amplitude Variations of an L/T Transition Brown Dwarf: Multi-Wavelength Observations of Patchy, High-Contrast Cloud Features","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"David Lafreni\\`ere, Didier Saumon, Etienne Artigau, Jacqueline Radigan, Mark Marley, Ray Jayawardhana","submitted_at":"2012-01-17T00:18:59Z","abstract_excerpt":"We present multiple-epoch photometric monitoring in the $J$, $H$, and $K_s$ bands of the T1.5 dwarf 2MASS J21392676+0220226 (2M2139), revealing persistent, periodic ($P=7.721\\pm$0.005 hr) variability with a peak-to-peak amplitude as high as 26% in the $J$-band. The light curve shape varies on a timescale of days, suggesting that evolving atmospheric cloud features are responsible. Using interpolations between model atmospheres with differing cloud thicknesses to represent a heterogeneous surface, we find that the multi-wavelength variations and the near-infrared spectrum of 2M2139 can be repro"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1201.3403","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"}