Photometric study of the OB star clusters NGC 1502 and NGC 2169 and mass estimation of their members at the University Observatory Jena

TL;DR

This study provides detailed multi-colour photometry and mass estimations for members of the OB clusters NGC 1502 and NGC 2169, confirming multiplicity in key components and enhancing understanding of their stellar properties.

Contribution

It offers new spectral type, absorption, and mass estimates for cluster members, and confirms the multiplicity of specific components using optical spectra, which was not previously done at this observatory.

Findings

Mass estimates for cluster members derived from photometry.

Confirmation of multiplicity in ADS 2984A and SZ Cam.

First optical spectrum analysis of these components at the observatory.

Abstract

In this work we present detailed photometric results of the trapezium like galactic nearby OB clusters NGC 1502 and NGC 2169 carried out at the University Observatory Jena. We determined absolute $BVRI$ magnitudes of the mostly resolved components using Landolt standard stars. This multi colour photometry enables us to estimate spectral type and absorption as well as the masses of the components, which were not available for most of the cluster members in the literature so far, using models of stellar evolution. Furthermore, we investigated the optical spectrum of the components ADS 2984A and SZ Cam of the sextuple system in NGC 1502. Our spectra clearly confirm the multiplicity of these components, which is the first investigation of this kind at the University Observatory Jena.