Abstract
The so-called age-metallicity degeneracy, which affects the optical spectral properties of stellar populations, is also present at mid-ultraviolet wavelengths. We give here the results for two reference objects: the Sun (assumed as representative of the turnoff star of a single stellar population) and M 32. Within a theoretical framework, we have explored the properties of the age-metallicity degeneracy by means of 17 spectroscopic indices from 2100 to 3100 Å: our preliminary results show a metallicity sensitivity parameter value of 1.7±1.2, which is compatible with the Worthey's value of 3/2 in the optical interval.
