P. Padoan et R. Jimenez, AGES OF GLOBULAR-CLUSTERS - BREAKING THE AGE-DISTANCE DEGENERACY WITHTHE LUMINOSITY FUNCTION, The Astrophysical journal, 475(2), 1997, pp. 580-583
We extend our previous method to determine globular cluster (GC) ages
using the luminosity function (Jimenez & Padoan). This method provides
at the same time independent determinations of distance and age of a
GC, by simply counting the number of stars found inside specified lumi
nosity bins. The main uncertainties in other traditional methods for d
etermining GC ages are absent (e.g., mixing length, color-T-eff calibr
ation, morphology of the color-magnitude diagram). If GC stellar count
s with statistical errors not larger than 3% are available, the age ca
n be determined with an uncertainty of about 0.5 Gyr, and the distance
modulus with an uncertainty of about 0.06 mag.