The proper and space motions of globular cluster NGC 4147 on Hipparcos system.

Abstract

The positions and proper motions of 82 stars in the field of the globular cluster NGC 4147, reduced with the 11 reference stars from the Hipparcos Catalogue, are kindly provided by M. Geffert, Bonn. 54 of these stars are used as reference stars to re-reduce the observations by Wang & Gupta (1998). Based on the new proper motions obtained from this reduction, a new absolute proper motion of the cluster, i.e. (-2.08±0.48, -3.07±0.46) mas/yr, is found (including the possible systematic deviation of 0.25 mas/yr for the Hipparcos Catalogue system). The apogalactic distance, 22.5 kpc, of the cluster is found from the new space motion.