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Lennart Lindegren. Profile picture.

Lennart Lindegren

Professor

Lennart Lindegren. Profile picture.

The Tycho-Gaia Astrometric Solution

Author

  • Lennart Lindegren

Summary, in English

Gaia DR1 is based on the first 14 months of Gaia's observations. This is not long enough to reliably disentangle the parallax effect from proper motion. For most sources, therefore, only positions and magnitudes are given. Parallaxes and proper motions were nevertheless obtained for about two million of the brighter stars through the Tycho-Gaia astrometric solution (TGAS), combining the Gaia observations with the much earlier Hipparcos and Tycho-2 positions. In this review I focus on some important characteristics and limitations of TGAS, in particular the reference frame, astrometric uncertainties, correlations, and systematic errors.

Department/s

  • Lund Observatory - Undergoing reorganization

Publishing year

2017-04-01

Language

English

Pages

41-48

Publication/Series

Proceedings of the International Astronomical Union

Volume

12

Issue

S330

Document type

Journal article review

Publisher

Cambridge University Press

Topic

  • Astronomy, Astrophysics and Cosmology

Keywords

  • astrometry
  • Catalogs
  • reference systems
  • stars: distances
  • stars: general

Status

Published

ISBN/ISSN/Other

  • ISSN: 1743-9213