Stellar Systems Group

Vicente, B.
IV Reunión sobre Astronomía Dinámica en Latino América (Eds. C. Allen, A. Ruelas, & R. Teixeira) Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias) Vol. 34, pp. 25-28 (2008)
12/2008

ABSTRACT

We present an astrometric catalogue of positions and proper motions derived from the Carte du Ciel plates of the San Fernando zone, which has a mean epoch 1901.4 and a limiting magnitude V 15. Digitization has been made using a conventional flatbed scanner. Special techniques have been developed to handle the combination of plate material and the large distortion introduced by the scanner. A variety of post-scan corrections are shown to be necessary. The equatorial coordinates are obtained on the ICRS system defined by Tycho-2. Comparison with the reference catalog indicates external errors of 0''.2. The UCAC2 Catalogue was used for second-epoch positions to derive proper motions with a mean accuracy of 1.2 mas yr-1 for the the well-measured stars. The usefulness of the resulting proper motion catalog is demonstrated by means of a proper-motion analysis of seven open clusters, ASCC 30, BOCHUM 3, NGC 2215, NGC 2302, NGC 2311, NGC 2323 and NGC 2548, determining individual membership probabilities and characterizing the gross properties of each cluster.