We present new multicolour CCD photometry of the central part of the globular cluster M3, mapping the precise position of ~120 RR Lyrae stars (RRab, RRd, RRc) on the horizontal branch (HB). The location of the double-mode variables (RRd) is in perfect agreement with recent theoretical results. We find a significant internal spread of metallicity amongst the RRab variables.
@article{arxiv.astro-ph/0004311,
title = {The Instability Strip of M3},
author = {G. Á. Bakos and J. Jurcsik},
journal= {arXiv preprint arXiv:astro-ph/0004311},
year = {2007}
}
Comments
2 pages, 1 figure, ASP Conf. Ser. 2000, vol. 203, pg. 255 - in press