  Near the end of the 16th century Wilhelm IV, Landgraf von Hessen-Kassel, set
up an observatory with the main goal to increase the accuracy of stellar
positions primarily for use in astrology and for calendar purposes. A new star
catalogue was compiled from measurements of altitudes and angles between stars
and a print ready version was prepared listing measurements as well as
equatorial and ecliptic coordinates of stellar positions. Unfortunately, this
catalogue appeared in print not before 1666, long after the dissemination of
Brahe's catalogue. With the data given in the manuscript we are able to analyze
the accuracy of measurements and computations. The measurements and the
computations are very accurate, thanks to the instrument maker and
mathematician Jost B\"urgi. The star catalogue is more accurate by a factor two
than the later catalogue of Tycho Brahe.
