Photometric and proper motion study of neglected open cluster NGC 2215

TL;DR

This study combines optical and infrared photometry with proper motion data to accurately determine the physical parameters of the neglected open cluster NGC 2215, including its size, age, distance, and metallicity.

Contribution

It provides the first detailed parameter estimation of NGC 2215 using multi-wavelength data and proper motions, and involves secondary school students in scientific research.

Findings

Core radius of 1.12 arcminutes

Age of approximately 700 million years

Distance of about 790 parsecs

Abstract

Optical UBVRI photometric measurements using the Faulkes Telescope North were taken in early 2011 and combined with 2MASS JHK$_s$ and WISE infrared photometry as well as UCAC4 proper motion data in order to estimate the main parameters of the galactic open cluster NGC 2215 of which large uncertainty exists in the current literature. Fitting a King model we estimate a core radius of 1.12$'\pm$0.04$'$ (0.24$\pm$0.01pc) and a limiting radius of $4.3'\pm$0.5$'$ (0.94$\pm$0.11pc) for the cluster. The results of isochrone fits indicates an age of $log(t)=8.85\pm0.10$ with a distance of $d=790\pm90$pc, a metallicity of $[Fe/H]=-0.40\pm0.10$ dex and a reddening of $E(B-V)=0.26\pm0.04$. A proportion of the work in this study was undertaken by Australian and Canadian upper secondary school students involved in the Space to Grow astronomy education project, and is the first scientific publication to have utilized our star cluster photometry curriculum materials.