INVESTIGADORES
PIATTI Andres Eduardo
congresos y reuniones científicas
Título:
The Overall Properties of Open Clusters Located 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
Lugar:
Chile
Reunión:
Congreso; Reunión Regional Latinoamericana de Astronomía; 2005
Resumen:
We present Washington photometry for red giant candidates in the open
clusters NGC 1817 and NGC 2251. Coravel radial velocities are used to
separate field stars from cluster giants. Effective temperatures and
metallicities are derived for each giant star. From new UBV and DDO
data, we also derive reddening and metal content for NGC 2251. We find
[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. No evidence for an age-metallicity relation is
found. However, a radial abundance gradient of -0.093 dex kpc^{-1} 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.