INVESTIGADORES
PIATTI Andres Eduardo
artículos
Título:
Photometric and Coravel observations of red giant candidates in three open clusters: membership, binarity, reddening and metallicity
Autor/es:
CLARIA OLMEDO, JUAN JOSÉ; MERMILLIOD, J.C.; PIATTI, ANDRÉS E.; PARISI, M.C.
Revista:
ASTRONOMY AND ASTROPHYSICS
Referencias:
Año: 2006 vol. 453 p. 91 - 99
ISSN:
0004-6361
Resumen:
Aims.We present new CORAVEL radial-velocity observations and
photoelectric photometry in the UBV and DDO systems for a sample of
potential members of the red-giant branches of NGC 6192, NGC 6208 and
NGC 6268, three open clusters projected close to the Galactic center
direction. We also examine the properties of a sample of 42 inner disk
open clusters projected towards almost the same direction as the three
clusters. Methods: .Cluster members and red field giants were
discriminated by using the CORAVEL radial-velocity data and by applying
two photometric criteria. Interstellar reddening and metal content of
the clusters were derived from combined BV and DDO data. Results:
.Cluster membership for five red giants in NGC 6192, three in NGC 6208
and three in NGC 6268 has been confirmed by the analysis of the
photometric and kinematic data. Photometric membership probabilities
show very good agreement with those obtained from CORAVEL radial
velocities. Three new spectroscopic binaries were discovered among the
red giants of NGC 6192 and NGC 6208. Mean radial velocities and E(B-V)
colour excesses were derived. Conclusions: .The overall
metallicities were found to be nearly solar for NGC 6208 and above solar
for NGC 6192 and NGC 6268. Most of the clusters located closer than 2
kpc from the Sun in the considered direction are slightly more reddened
than the absorption resulting from the Baade's window absorption law.