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00925njm 22002777a 4500 dc Gaia Collaboration author Carrasco, José Manuel (Carrasco Martínez) author Figueras Siñol, Francesca author Jordi i Nebot, Carme author Luri Carrascoso, Xavier author Antoja, T. (Teresa) author Fabricius, Claus author Balaguer Núñez, María de los Dolores author Portell i de Mora, Jordi author Romero Gómez, Mercè author Castañeda Pons, Javier Bernardo author Masana Fresno, Eduard author Weiler, Michael author 2024-09-20T15:21:55Z 2024-09-20T15:21:55Z 2021-04-28 2024-09-20T15:21:55Z Context. Gaia Early Data Release 3 (Gaia EDR3) provides accurate astrometry for about 1.6 million compact (QSO-like) extragalactic sources, 1.2 million of which have the best-quality five-parameter astrometric solutions. Aims. The proper motions of QSO-like sources are used to reveal a systematic pattern due to the acceleration of the solar system barycentre with respect to the rest frame of the Universe. Apart from being an important scientific result by itself, the acceleration measured in this way is a good quality indicator of the Gaia astrometric solution. Methods. The effect of the acceleration is obtained as a part of the general expansion of the vector field of proper motions in Vector Spherical Harmonics (VSH). Various versions of the VSH fit and various subsets of the sources are tried and compared to get the most consistent result and a realistic estimate of its uncertainty. Additional tests with the Gaia astrometric solution are used to get a better idea on possible systematic errors in the estimate. Results. Our best estimate of the acceleration based on Gaia EDR3 is (2.32±0.16)×10−10 m s −2 (or 7.33±0.51 km s −1 Myr −1 ) towards α=269.1∘±5.4∘ , δ=−31.6∘±4.1∘ , corresponding to a proper motion amplitude of 5.05±0.35 μ as yr −1 . This is in good agreement with the acceleration expected from current models of the Galactic gravitational potential. We expect that future Gaia data releases will provide estimates of the acceleration with uncertainties substantially below 0.1 μ as yr −1 . Fotometria Sistema solar Astrometria Photometry Solar system Astrometry Gaia Early Data Release 3: Acceleration of the solar system from Gaia astrometry