The Stellar Population and Orbit of the Galactic Globular Cluster Palomar 3

TL;DR

This paper presents deep photometric and spectroscopic data for the distant globular cluster Palomar 3, estimates its orbital parameters, and discusses its properties in context with similar clusters, highlighting the need for more precise data.

Contribution

It provides new photometric, spectroscopic, and orbital data for Palomar 3, enhancing understanding of its properties and origin compared to prior studies.

Findings

Estimated orbital parameters of Palomar 3

Determined age, metallicity, and distance of the cluster

Highlighted the need for more accurate proper motion and chemical data

Abstract

Deep stellar photometry of one of the most distant Galactic globular clusters, Palomar 3, based on frames taken with the VLT in Johnson-Cousins broadband V and Ifilters is presented, together with medium-resolution stellar spectroscopy in the central region of the cluster obtained with the CARELEC spectrograph of the Observatoire de Haute Provence and measurements of the Lick spectral indices for the integrated spectrum. Computations of the orbital parameters of Palomar 3 and nine Galactic globular clusters with similar metallicities and ages are also presented. The orbital parameters, age, metallicity, and distance of Palomar 3 are estimated. The interstellar absorption is consistent with and supplements values from the literature. The need to obtain more accurate data on the proper motions, ages, and chemical compositions of the cluster stars to elucidate the origin of this globular cluster is emphasized.