Star clusters or asterisms? 2MASS CMD and structural analyses of 15 challenging targets

TL;DR

This study analyzes 15 challenging celestial objects to determine whether they are true star clusters or mere asterisms, using 2MASS CMD and structural data, addressing classification conflicts.

Contribution

It provides detailed photometric and structural analyses of ambiguous objects, clarifying their nature and introducing new insights into their classification.

Findings

Some objects confirmed as star clusters

Others identified as asterisms or ambiguous

First-time analyses for several targets

Abstract

(Abridged) Poorly-populated star clusters may have photometric and structural properties not much different from asterisms, to the point that, in some cases, widely-used databases present conflicting classifications. We investigate the nature of a sample of challenging targets that have been classified either as star clusters or asterisms in different studies. A few objects are studied for the first time.