The Tycho double star catalogue

We report the discovery of 13 251 visual double stars, mostly with separations between 0.3 and 1 arcsec, from a dedicated re-reduction of the Tycho data from the star mapper of the ESA Hipparcos satellite. The new doubles are combined with 18 160 WDS systems identified in the Tycho-2two, and 1220 new Tycho-2 doubles, to form the Tycho Double Star Catalogue, TDSC, a catalogue of absolute astrometry and B_T, V_T photometry for 66 219 components of 32 631 double and multiple star systems. We also include results for 32 263 single components for systems unresolved in TDSC, and a supplement gives Hipparcos and Tycho-2one data for 4777 additional components. The TDSC thus contains a total of 103 259 entries. Cross identifications are given to WDS, HD, Hipparcos and Tycho-2. Based on observations made with the ESA Hipparcos astrometry satellite. The catalogue is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/384/180