The extremely metal-poor globular cluster M30 (NGC 7099)

J.J. CLARIÁ, D. MINNITI, M.N. GÓMEZ

Córdoba

Conferencia; II IAU Regional Meeting of Extragalactic Astronomy; 1987

Observatorio Astronómico de Córdoba

Photoelectric DDO and BV photometry is presented for a sample of red giants of the globular cluster M30(NGC 7099). The mean metallicity estimated, [Fe/H] < -2.14, places M30 as the most metal-deficient globular cluster presently known, thus extending the abundance scale of the ranking method of Hesser et al. (1977). No CN-strength variations exist among the cluster giants. Although the morphology of Bolte´s (1987) CCD colour-magnitude diagram supports the present abundance results, it would be valuable to confirm them by spectroscopic methods.