Note that the errors on the
proper motions are large (∼50mas/yr), and therefore the positions
computed at an epoch different from 1991.25 have a large (∼0.4")
uncertainty.
The Tycho Epoch Photometry data can
be accessed from the morePhoto column
(includes VT, BT and Hp photometric data for Hipparcos stars
[HIPftr_576x310http://cdsarc.cds.unistra.fr/ftp/cats/I/239/filter.gif
filter responses]