The big astrometric Catalogue ARIHIP
The constituentsAs in the case of our FK6, (using ground based data provided by the FK5 to improve Hipparcos' results), we also used Boss' General Cat. (GC) to increase the number of stars with such better data: The combination of HIPPARCOS and GC data gives improved results for 20 069 stars. This catalogue - named GC+HIP - gives proper motions (pm) with a typical mean error of 0.66 mas/year (about a factor of 1.2 better than Hipparcos for this stars). We then used the proper motions of the Tycho-2 Catalogue to improve the pm for an additional huge number of Hipparcos stars. This catalogue giving pm with a typical mean error of 0.83 mas/year (about a factor of 1.3 better than Hipparcos for this sample) is called TYC2+HIP. The FK6 Part I is providing pm with a typical mean error of 0.35 mas/year, the FK6 part III with a typical mean of 0.59 mas/year.
These three catalogues were presented/published 1999, 2000, and 2001. They are available online:
The catalogue ARIHIPThe catalogue ARIHIP has been constructed by selecting the 'best data' for a given star from the three combination catalogues mentioned above. It provides 'best data' for 90 842 stars with a typical mean error of 0.89 mas/year (about a factor of 1.3 better than Hipparcos for this sample of stars). It was presented in 2001 and published online:
Contact: C. Dettbarn