{"paper":{"title":"Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.GA","authors_text":"A. Andrei, A. Bombrun, A. Butkevich, A. de Torres, A. Fienga, A. Hutton, A. Mora, A. Riva, A. Spagna, A. Vecchiato, B. Bucciarelli, B. Holl, C. Barache, C. Fabricius, D. Busonero, D. Hobbs, D. Michalik, E. Fraile, E. Joliet, F. de Felice, F. Figueras, F. Mignard, F. Raison, F. Taris, G. Bourda, G. Comoretto, G. Gracia, H. Lenhardt, H. Siddiqui, H. Steidelm\\\"uller, I. Serraller, I. Steele, J. Berthier, J. Casta\\~neda, J. de Bruijne, J. Hern\\'andez, J.J. Gonz\\'alez-Vidal, J. Marchant, J. Osorio, J. Portell, J. Torra, L. Bianchi, L. Lindegren, M. Altmann, M. Biermann, M. Clotet, M. Crosta, M. Davidson, M. Gai, M.G. Lattanzi, M. Hauser, M. Ramos-Lerate, M. Sarasso, M. Soffel, N. Bach, N.C. Hambly, N. Garralda, P. Charlot, P.J. McMillan, P. Parsons, R. Drimmel, R. Geyer, R. Guerra, R. Messineo, R. Morbidelli, R. Smart, S. Anton, S. Bouquillon, S. Jordan, S. Klioner, S. Liao, S. Zschocke, T. Br\\\"usemeister, T. Carlucci, T. Lister, U. Abbas, U. Bastian, U. Becciani, U. Lammers, U. Stampa, W. L\\\"offler, W. O'Mullane, W. van Reeven","submitted_at":"2016-09-14T14:51:58Z","abstract_excerpt":"Gaia Data Release 1 (Gaia DR1) contains astrometric results for more than 1 billion stars brighter than magnitude 20.7 based on observations collected by the Gaia satellite during the first 14 months of its operational phase. We give a brief overview of the astrometric content of the data release and of the model assumptions, data processing, and validation of the results. For stars in common with the Hipparcos and Tycho-2 catalogues, complete astrometric single-star solutions are obtained by incorporating positional information from the earlier catalogues. For other stars only their positions"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1609.04303","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"}