Complex investigation of the star formation region in Orion constellation.

The proper motions of 54 young stars in the Ori OB1 cluster has been specified. The contraction of the cluster in the time scale of ≈3×10⁶years is discovered, and the cluster rotation with the period of ≈6×10⁶years is confirmed as well. The cluster velocity ≈-10 km/s is determined from spatial velocities of 26 stars. This means that the cluster was situated in the symmetry plane of the Galaxy some 1.4×10⁷years ago, that coincides with the oldest subcluster age of the association.