@article {23963,
	title = {BVRI photometry of the galactic globular cluster NGC 6779},
	volume = {348},
	year = {2004},
	month = {2004/03/1},
	pages = {1157 - 1163},
	abstract = {We present B, V, R and I photometry for NGC 6779 (M56), a metal-poor globular cluster in the galactic halo. The observations were performed using the 1.3-m telescope at Skinakas Observatory, in Crete. The reddening of the cluster was found to be E(B-V) = 0.32 {\textpm} 0.02 [E(V-I) = 0.43 {\textpm} 0.02], significantly higher than previous estimates. The metal abundance of the cluster was derived from various parametrizations of red giant branch characteristics and it was found to be [Fe/H]<SUB>ZW</SUB>=-2.20 {\textpm} 0.12 dex on the Zinn-West metallicity scale, or [Fe/H]<SUB>CG</SUB>=-2.00 {\textpm} 0.21 dex on the Carretta-Gratton scale. The distance modulus of the cluster is estimated to be (m-M)<SUB>V</SUB>= 15.62 {\textpm} 0.26 (or 14.62, if we correct for the reddening to the cluster). The horizontal branch of NGC 6779 shows a clear gap at (B-V)<SUB>o</SUB>= 0.0. Finally, the revised value for the metallicity of NGC 6779 led to a revision of its age to 13 Gyr, using the age-index calibrations of Salaris \&amp; Weiss.},
	isbn = {0035-8711},
	url = {https://ui.adsabs.harvard.edu/abs/2004MNRAS.348.1157H},
	author = {Hatzidimitriou, D. and Antoniou, V. and Papadakis, I. and Kaltsa, M. and Papadaki, C. and Papamastorakis, I. and Croke, B. F. W.}
}
