Colour-magnitude diagrams of star clusters in the Magellanic clouds from wide-field electronography. II. NGC 2210.

The authors report photometric observations in B and V to V = 23.1 for 235 stars in an annular field 39arcsec ≤ R ≤ 60arcsec centered on the LMC cluster NGC 2210. Corrected for the effects of non-member stars, the colour-magnitude diagram (CMD) of NGC 2210 is found to closely resemble the diagram for the old, very metal-poor galactic globular cluster M92. The detailed CMD for the cluster then confirms the assignment of NGC 2210 by Searle et al. (1980) to the oldest, most metal-poor population in the LMC (SWB class VII), based on its integrated colours. From the fit of the CMD to those of M92 and M3, the authors find for NGC 2210 a distance modulus of (m-M)₀ = 17.9 - 18.4 under various assumptions concerning the reddening and metal abundance of the cluster and the absolute magnitudes of its HB stars.