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

TL;DR

This study provides the first spectroscopic analysis of NGC 1883, determining its metallicity, velocity, and age, and confirms its status as an outer disk intermediate-age open cluster, contributing to understanding the Galactic abundance gradient.

Contribution

It offers the first multi-epoch spectroscopic data for NGC 1883, refining its parameters and confirming its role in studying the Galactic disk's chemical evolution.

Findings

NGC 1883 has a metallicity of [Fe/H] = -0.20±0.22.

The cluster's age is approximately 650 Myr.

It is located at a Galactocentric distance of about 12.3 kpc.

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 is as metal poor as globular clusters in the Halo. Besides, being one of the few outer Galactic disk intermediate-age open clusters known so far, it is an ideal target to improve our knowledge 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's basic parameters more reliable. We find that the cluster has a mean metallicity of [Fe/H] = -0.20$\pm$0.22, from which we infer an age (650$^{+70}_{-70}$ Myr) close to the Hyades one and a Galactocentric distance of 12.3$^{+0.4}_{-0.2}$ kpc. The metal abundance, kinematics, and position make NGC 1883 a genuine outer disk intermediate-age open cluster. We confirm that in the outer Galactic disk the abundance gradient is shallower than in the solar vicinity.