lola nuñez

Absolute proper motions, their corresponding errors and membership probabilities of 501 stars in the intermediate-age open cluster NGC 2548 region are determined from MAMA measurements of 10 photographic plates. The plates have the maximum epoch difference of 82 years and they were taken with the double astrograph at Zô-Sèstation of Shanghai Observatory, which has an aperture of 40 cm and a plate scale of 30 arcsec mm-1. The average proper motion precision is 1.18 mas yr-1. These proper motions are used to determine the membership probabilities of stars in the region. The number of stars with membership probabilities higher than 0.7 is 165. Table 5 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http:// cdsweb.u-strasbg.fr/cgi-bin/qcat?J/ A+A/381/464, and by e-mail request to Lola.Balaguer@am.ub.es MAMA (Machine Automatique àMesurer pour l'Astronomie, http://dsmama.obspm.fr) is developed and operated by INSU/CNRS and Observatoire de Paris.