2000A&A...357..149D

Relative proper motions and cluster membership probabilities of 30 stars within an area of 14' of diameter centered in the open cluster NGC 1662 (α=04^h48^m, δ=+10°56') are determined by combining positions of stars observed by the Valinhos CCD meridian circle with those from other astrometric catalogues. Our basic source for first epoch of stars brighter than B=13 magnitudes is the AC2000 Catalogue, which provides a time baseline of about 90 years, whereas 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 (1990A&A...237...54Z) method. 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.