Hubble data for this release were obtained from the following HST proposals:
9750: PI: K. Sahu (STScI), R. Gilliland (Pennsylvania State University), H. Bond (STScI/Pennsylvania State University), T. Brown (University of Colorado), S. Casertano and M. Livio (STScI), D. Minniti (Pontificia Universidad Católica de Chile), N. Panagia (STScI), A. Renzini (Osservatorio Astronomico di Padova, Italy), R. Rich (UCLA), and M. Zoccali (Pontificia Universidad Católica de Chile); and proposal;
12586: PI: K. Sahu (STScI), H. Bond (STScI/Pennsylvania State University), T. Brown, H. Ferguson, J. Anderson, and S. Casertano (STScI), M. Dominik (University of St. Andrews), A. Udalski (Warsaw University), M. Livio (STScI), Y. Perrott (University of Cambridge), M. Albrow (University of Canterbury), P. Yock (University of Auckland), C. Fryer (Los Alamos National Laboratory), S. Mao (Manchester University), and I. Bond (Massey University).
The international team of astronomers in this study includes: A. Calamida, K. Sahu, S. Casertano, and J. Anderson (STScI), S. Cassisi (INAF - Osservatorio Astronomico di Teramo, Italy), M. Gennaro, M. Cignoni, T. Brown, N. Kains, H. Ferguson, and M. Livio (STScI), H. Bond (STScI/Pennsylvania State University), R. Buonanno (INAF - Osservatorio Astronomico di Teramo, Italy, and Università di Roma Tor Vergata, Roma, Italy), W. Clarkson (University of Michigan, Dearborn), I. Ferraro (INAF - Osservatorio Astronomico di Teramo, Italy), A. Pietrinferni (INAF - Osservatorio Astronomico di Roma, Italy), M. Salaris (Astrophysics Research Institute/Liverpool John Moores University), and J. Valenti and J. Sokol (STScI).
