T. Brüsemeister

TL;DR: Gaia as discussed by the authors is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach.

TL;DR: The first data release from the Gaia mission contains accurate positions and magnitudes for more than a billion sources, and proper motions and parallaxes for the majority of the 2.5 million HIPPARCOS and Tycho-2 stars as mentioned in this paper.

TL;DR: In this article, the first parallax measurements of the primary standard candles of the cosmological distance ladder, that involve astrometry collected by Gaia during the initial 14 months of science operation, are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS).

TL;DR: An error occurred during the production process of the original published version as mentioned in this paper and the following names were omitted from the author list: R. Haigron, D. Hatzidimitriou, M. Hauser, E. Haywood, U. Heiter, J. Heu, T. Hilger.