First estimates of the fundamental parameters of the very small open cluster Ruprecht1

PIATTI, ANDRÉS E.; CLARIA OLMEDO, JUAN JOSÉ; PARISI, M.C.; AHUMADA, A.V.

Boletín de la Asociación Argentina de Astronomía

G. Dubner, D. Garcia Lambas, A.E. Piatti

Año: 2009

New CCD observations with the Washington C and T1 filters in the field of the open cluster Ruprecht\1 are presented. The cluster turned out to be very small, its linear radius being 2.6 +- 0.2 pc. Ruprecht1 is moderately reddened [E(B-V) = 0.25] and moderately young (~ 230 Myr). Heliocentric distances of 1.9 +-0.4 kpc and 1.5 +- 0.3 kpc are determined for Z (metallicity) = 0.02 and 0.008, respectively, although evidence is presented favouring a solar metal content rather than a subsolar one. We compare the cluster properties with those of known open clusters located within 1 kpc around it.