The Hipparcos mission and galactic open clusters and NGC 7538 star forming regions

Abstract

We present some results of a study of the galactic open cluster population. This study is based on the all-sky catalogue ASCC-2.5 compiled from Tycho-2, Hipparcos and other catalogues. Screening the ASCC-2.5 resulted in the identification of 520 known clusters and the detection of 130 new ones. A uniform combined kinematic-photometric cluster membership was established for these objects and new uniform scales of cluster structure (angular sizes), kinematics (average proper motions and radial velocities), photometry (reddening and distance) and evolution (age) were established. Two parts of our more extended open cluster population study (some details on the spatial and age distributions of open clusters) are presented here.