SCYON Abstract

Received on May 31 2007

The anticenter old open cluster NGC 1883: radial velocity and metallicity

AuthorsSandro Villanova (1), Gustavo Baume (2), and Giovanni Carraro (1)
Affiliation(1) Universita' di Padova
(2) Universidad de La Plata
Accepted byMonthly Notices of the Royal Astronomical Society
Contactsandro.villanova@unipd.it
URLhttp://www.arxiv.org/abs/0705.2300
Links NGC 1883

Abstract

Having already reported on the first photometric study of the intermediate-age open cluster NGC 1883 (Carraro et al. 2003), we present in this paper the first spectroscopic multi-epoch investigation of a sample of evolved stars in the same cluster. The aim is to derive the cluster membership, velocity and metallicity, and discuss recent claims in the literature (Tadross 2005) that NGC 1883 would be as metal poor as globular clusters in the Halo. Besides, being one of the few outer Galactic disk old open clusters known so far, it is an ideal target to improve our knowlwdge of the Galactic disk radial abundance gradient, that is a basic ingredient for any chemical evolution model of the Milky Way. The new data we obtained allow us to put NGC 1883 basic parameter on a firmer pace. We find that the cluster has a mean metallicity [Fe/H] = -0.20±0.22, from which we infer an age (650+70-70 Myr) close to the Hyades one and a Galactocentric distance of 12.3+0.4-0.2kpc. The metal abundance, kinematics, and position make NGC 1883 a genuine outer disk old open cluster. A time more, we confirm that in the outer Galactic disk the abundance gradient is shallower than in the solar vicinity.