The Hipparcos-2 Catalogue - Hipparcos
The Hipparcos-2 Catalogue
A new reduction of the astrometric data as produced by the Hipparcos mission was published in 2007, claiming accuracies for nearly all stars brighter than magnitude Hp = 8 to be better, by up to a factor 4, than in the original catalogue. This catalogue is known as the Hipparcos-2 Catalogue.
Details of the data reduction, catalogue construction and verification of the results can be found in Hipparcos, the New Reduction of the Raw Data.