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.

Reference Papers:
The catalogue is described in "Validation of the new Hipparcos reduction", F. van Leeuwen, A&A, 474, 653-664, (2007).

Details of the data reduction, catalogue construction and verification of the results can be found in Hipparcos, the New Reduction of the Raw Data.

Catalogue Access:
The data is available from CDS in VizieR. The Hipparcos-2 Catalogue is also available from ESA Sky and from the Gaia Archive.