Astron. Astrophys. 360, 391-398 (2000)

The Hipparcos, Tycho, TRC, and ACT catalogues

A whole sky comparison of the proper motions

R. Hoogerwerf ¹ and A. Blaauw <sup>1,2

1</sup> Sterrewacht Leiden, Postbus 9513, 2300 RA Leiden, The Netherlands
² Kapteyn Instituut, Postbus 800, 9700 AV Groningen, The Netherlands

Received 3 November 1999 / Accepted 14 April 2000

Abstract

We present a whole sky comparison of the proper motions contained in the Hipparcos Catalogue, the Tycho Catalogue, the Tycho Reference Catalogue (TRC), and the Astrographic Catalogue plus Tycho Reference Catalogue (ACT). The catalogues are compared in the 20 declination zones defined by the original Carte du Ciel project. We find that (1) the proper-motion errors in the ACT Catalogue are underestimated in all zones, sometimes by as much as 30%. (2) There are systematic differences, as large as 1.2 mas yr^-1, between the proper motions in the TRC and ACT depending on the zone. We confirm the known underestimation of the proper-motion error (by as much as 40%) of the faint stars ( mag) in the Tycho Catalogue.

Key words: catalogs astrometry reference systems

Send offprint requests to: R. Hoogerwerf

Correspondence to: hoogerw@strw.leidenuniv.nl

This article contains no SIMBAD objects.

Contents

• 1. Introduction
• 2. Catalogues
  • 2.1. Hipparcos and Tycho
  • 2.2. TRC and ACT
  • 2.3. Tycho 2
• 3. Comparison
  • 3.1. Method
  • 3.2. Results
    • 3.2.1. Underestimation of ACT proper-motion errors
    • 3.2.2. Faint Tycho stars
    • 3.2.3. Systematic differences between TRC and ACT
    • 3.2.4. TRC and ACT correlated
    • 3.2.5. Peculiar zones
• 4. An independent comparison
• 5. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: July 27, 2000
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