INVESTIGADORES
PIATTI Andres Eduardo
artículos
Título:
Overall properties of open clusters projected towards the galactic anticenter direction: Washington photometry of NGC 1817 and NGC 2251
Autor/es:
PARISI, M.C.; CLARIA OLMEDO, JUAN JOSÉ; PIATTI, ANDRÉS E.; GEISLER, DOUG
Revista:
Bol. Asociación Argentina de Astronomía
Referencias:
Año: 2005 vol. 48 p. 220 - 225
Resumen:
We present Washington photometry for red giant candidates in the open
clusters NGC 1817 and NGC 2251. Published radial velocities are used to
separate field stars from cluster giants. Effective temperatures and
metal abundances are derived for each star. From new UBV and DDO
photometric data, we also derive reddening and metal content for NGC
2251. The resulting mean metallicities are [Fe/H] = -0.33 + 0.08 and
-0.20 + 0.05 for NGC 1817 and NGC 2251, respectively. We reexamine the
overall properties of a sample of 30 clusters in the Galactic anticenter
direction with distances, ages and metallicities available. This cluster
sample presents no evidence of an abundance gradient perpendicular to
the Galactic plane, nor is an age-metallicity relation found. However, a
radial abundance gradient of -0.093 dex/kpc is derived over a
Galactocentric distance of 14 kpc. This value practically does not
change when all clusters with basic parameters known up to this date are
considered.