{"paper":{"title":"Optical and infrared photometry of new very low-mass stars and brown dwarfs in the Sigma Orionis cluster","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"(2) Laeff-Inta, 3) ((1) Instituto de Astrofisica de Canarias, (3) Consejo Superior de Investigaciones Cientificas, La Laguna, Madrid, M. R. Zapatero Osorio (2), R. Rebolo (1, Spain, Spain), V. J. S. Bejar (1)","submitted_at":"2004-04-06T10:11:04Z","abstract_excerpt":"We present an RI photometric survey covering an area of 430 arcmin^2 around the multiple star Sigma Orionis. The observations were conducted with the 0.8 m IAC-80 Telescope at the Teide Observatory. The survey limiting R and I magnitudes are 22.5 and 21, and completeness magnitudes 21 and 20, respectively. We have selected 53 candidates from the I vs. R-I colour-magnitude diagram (I=14-20) that follow the previously known photometric sequence of the cluster. Adopting an age of 2-4 Myr for the cluster, we find that these objects span a mass range from 0.35 Msol to 0.015 Msol. We have performed "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0404125","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"}