Lennart Lindegren
Professor
The Tycho-Gaia Astrometric Solution
Author
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