A PROPER MOTION SURVEY .1. HYADES AND UMA MOVING GROUPS

We analyze the results of a proper motion survey in a couple of ESO R 5-degrees x 5-degrees fields, finding evidence for faint (and primarily red) members of the Hyades and UMa moving groups. By using the velocity ellipsoid of the Hyades and UMa streams and the technique described by Mendez & Ruiz [AJ, 103, 911 (1992)] we estimate number densities and nonbiased velocity dispersions for each moving group. Our results suggest that the Hyades moving group extends at least 96 pc in the solid angle covered by our survey, while the UMa moving group shows a decrease in density past 36 pc, indicating that we are looking beyond it. The large tangential velocity dispersion for both moving groups suggest on the other hand that they are not gravitationally bound.