{"paper":{"title":"Gaia Data Release 2: The astrometric solution","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"A. Abreu, A. Andrei, A. Bombrun, A. de Torres, A. Fienga, A. Hutton, A. Mora, A. Riva, A. Spagna, A. van Elteren, A. Vecchiato, B. Bucciarelli, B. Holl, C. Barache, C. Crowley, C. Fabricius, C. Stephenson, D. Busonero, D. Hobbs, D. Michalik, E. Anglada, E. Fraile, E. Licata, E. Poggio, E. Salguero, E. Sciacca, F. de Felice, F. Mignard, F. Taris, F. van Leeuwen, G. Bourda, G. Comoretto, G. Gracia, H. Lenhardt, H. Siddiqui, H. Steidelmuller, I. Steele, J. Castaneda, J. de Bruijne, J. Hernandez, J.J. Gonzalez-Vidal, J. Marchant, J.-M. Martin-Fleitas, J. Portell, J. Torra, L. Balaguer-Nunez, 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, N.C. Hambly, N. Cheek, N. Garralda, N. Rowell, P. Charlot, P. Esquej, P.J. McMillan, R. Buzzi, R. Cancelliere, R. Drimmel, R. Geyer, R. Guerra, R.L. Smart, R. Messineo, R. Morbidelli, S. Bertone, S. Bouquillon, S. Jordan, S. Klioner, S. Liao, T. Brusemeister, T. Carlucci, T. Hilger, T. Lister, U. Abbas, U. Bastian, U. Becciani, U. Lammers, U. Stampa, W. Hofmann, W. Loffler, W. van Reeven","submitted_at":"2018-04-25T06:25:16Z","abstract_excerpt":"Gaia Data Release 2 (Gaia DR2) contains results for 1693 million sources in the magnitude range 3 to 21 based on observations collected by the European Space Agency Gaia satellite during the first 22 months of its operational phase. We describe the input data, models, and processing used for the astrometric content of Gaia DR2, and the validation of these results performed within the astrometry task. Some 320 billion centroid positions from the pre-processed astrometric CCD observations were used to estimate the five astrometric parameters (positions, parallaxes, and proper motions) for 1332 m"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.09366","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"}