Standard Globular Cluster Giant Branches in the (M(I), (V - I)o) Plane
Abstract
CCD photometry in the V, I (Cousins) bandpasses is presented for a large number of giants in eight galactic globular clusters. The (V-I)sub O color of the giant branch accurately ranks clusters in metal abundance, and can accordingly be used to ascertain both metal abundances and abundance dispersions in old stellar populations. A relation is derived that yields the bolometric correction to the I magnitude for red giants as a function of (V-I)sub O color. With this relation, and the assumption of the LDZ distance scale, the bolometric magnitudes of the brightest red giants in the clusters were determined; good agreement is obtained with the predictions of stellar evolution theory for the luminosity of the He core flash.
- Publication:
-
The Astronomical Journal
- Pub Date:
- July 1990
- DOI:
- 10.1086/115500
- Bibcode:
- 1990AJ....100..162D
- Keywords:
-
- Abundance;
- Astronomical Photometry;
- Asymptotic Giant Branch Stars;
- Color-Magnitude Diagram;
- Globular Clusters;
- Bolometers;
- Charge Coupled Devices;
- Heavy Elements;
- Metallicity;
- Stellar Color;
- Stellar Magnitude;
- Astrophysics;
- CLUSTERS: GLOBULAR