CCD photometry of the distant southern globular cluster NGC 5824

Open Access
Publisher Website
Google Scholar
Abstract
CCD observations have been used to generate a V,(B–V) colour–magnitude diagram for the distant globular cluster NGC 5824. The sample consists of 285 stars reaching V = 20.5, and a well-defined blue horizontal branch is observed for the first time. Assuming a reddening of |$E(B-V)=0.13$|⁠, the colour of the giant branch at the level of the horizontal branch is determined to be |$(B-V)_{\text{o,g}}=0.77$| and the apparent distance modulus |$(V-M_\text v)=18.0\pm0.2$|⁠. From these, a value of [Fe/H] = − 1.7 and a heliocentric distance of 33 (±3) kpc have been estimated for the cluster. This yields a galacto-centric distance of 25 kpc which, when combined with Hesser, Shawl & Meyer's recent radial-velocity determination, enables the representative point of the cluster to be plotted in Lynden-Bell's velocity–distance diagram where its location is consistent with a conventional value of the mass of our Galaxy.

This publication has 0 references indexed in Scilit: