Relative proper motions and cluster membership probabilities of 30 stars wi
thin an area of 14' of diameter centered in the open cluster NGC 1662 (alph
a = 04(h)48(m), delta = +10 degrees 56') are determined by combining positi
ons of stars observed by the Valinhos CCD meridian circle with those from o
ther astrometric catalogues.
Our basic source for first epoch of stars brighter than B = 13 magnitudes i
s the AC2000 Catalogue, which provides a time baseline of about 90 years, w
hereas the USNO-A2.0 Catalogue is used for fainter stars, providing a time
baseline of about 40 years in this region.
Average accuracies in proper motion of 2 mas/yr and 7 mas/yr are achieved,
respectively, when the AC2000 or the USNO-A2.0 is used.
Membership determination is obtained by applying the Zhao & He (1990) metho
d. The cluster proper motion was found to be (-3.2 +/- 0.6) mas/yr in right
ascension and (-1.6 +/- 0.6) mas/yr in declination.