Tycho Catalogue

The Tycho Catalogue contains data collected as part of the overall mission of the Hipparcos satellite; it represents a catalogue of position, parallax, proper motion, and magnitude data collected for over one million stars. In most cases, its precision is much greater than all earlier catalogues. About the only case in which the Tycho data would be ignored would be if Hipparcos data (see Hipparcos Catalogue) is available instead. The Tycho data is essentially a survey of all stars that were bright enough to be measured by the detector, and is essentially complete to about magnitude 10.5, with somewhat incomplete coverage to magnitude 11 or 11.5.