The metallicity range of variables in M 3
Konkoly Observatory of the Hungarian Academy of Sciences, PO Box 67, 1525 Budapest, Hungary
Corresponding author: email@example.com
Accepted: 13 March 2003
The recently published spectroscopic metallicities of RR Lyrae stars in M 3 (Sandstrom et al. [CITE]) show a relatively wide range of the measured [Fe/H] values. As no dependence of the metallicities on either minimum temperature or period was found, they concluded that no real metallicity spread was detected. Comparing these spectroscopic metallicities with the [Fe/H] values calculated from the Fourier parameters of the light curves of the variables a correlation between the results of the two metallicity determinations emerges. As a consequence of the complete independence of the spectroscopic and photometric metallicities, this correlation points to a real metallicity spread in M 3. The absolute magnitudes of the variables follow a similar trend with both the spectroscopic and photometric metallicities as the general relation predicts. This fact supports that the detected range in the metallicities of the variables is real.
Key words: globular clusters: individual: M 3 / stars: abundances / stars: variables: RR Lyr / stars: horizontal-branch / stars: population II
© ESO, 2003