We thank F. Arenou for the combined evaluation of VLBA and Hipparcos astrometry data. The Very Large Baseline Array and the Very Large Array are operated by Associated Universities, Inc. under contract with the US National Science Foundation. The work at ETH Zürich is financially supported by the Swiss National Science Foundation (grant No. 20-046656.96).
© European Southern Observatory (ESO) 2000
Online publication: December 17, 1999