Description
Relative proper motions and membership probabilities of 1046 stars in the open cluster M67 are are determined from PDS measurements of 9 plate pairs taken with the double astrograph at the Zo-Se station Shanghai Observatory, which has an aperture of 40cm, a focal length of 6.9m and a scale of 30"/mm. The number of stars with membership probabilities higher than 0.8 and at a distance less than 45' from the field center is 282. The average standard errors of proper motions vary from +/-0.0004"/yr for bright stars in the inner part of the field to some +/-0.0015"/yr for faint stars in the outer part of the cluster. It is shown by a detailed discussion that the proper motions and membership probabilities of the stars determined in this paper are in quite satisfactory agreement wit those obtained by Sanders (1977A&AS...27...89S) or Girard et al. (1989AJ.....98..227G).
|