ON THE ACTIVITY AND ORBIT OF THE GEMINIDS METEOROID STREAM

The activity of the Geminids meteor shower is studied on the basis of radio observations carried out by the Budrio meteor radar in 1986. The 1986 Geminids have displayed as a distinct meteor shower with an asym metric curve of activity, the duration between the points of one-quart er strength being 6 days and the maximum at the solar longitude of abo ut 260.75-degrees (1950.0). The mean orbit and radiant ephemeris of th e Geminids are derived on the basis of 191 precise photographic orbits available from the IAU Meteor Data Centre in Lund. Over a time span o f 50 years, the semi-major axis, eccentricity and perihelion distance of the stream exhibit variations following the trend of the stream evo lution suggested by Williams and Wu.