Observations of minor planets by Hipparcos

The main goal of Hipparcos is to build a catalogue of stars but 48 minor planets are bright enough and sufficiently pointlike to be observed also. This paper describes some aspects of the minor planets astrometric data reduction procedure. Comparison to the calculated places is given as well as a first attempt to minor planets orbital elements correction. The data collected after a year and a half show that minor planets position can be given with an accuracy of about 0.01 arcsecond. This great precision is balanced by the fact that observations are insufficiently numerous and not uniformly distributed to yield valuable results on the part of the osculating elements.