[1] Univ Concepcion, Dept Astron, Concepcion, Chile
[2] Univ Warsaw Observ, PL-00478 Warsaw, Poland
[3] Carnegie Observ, Pasadena, CA 91101 USA
[4] Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy
[5] INAF Osservatorio Astron Roma, I-00040 Monte Porzio Catone, Italy
[6] Univ Pisa, Dipartimento Fis, I-56127 Pisa, Italy
[7] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy
[8] UNS CNRS OCA, UMR7293, Lab Lagrange, F-06300 Nice, France
[9] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA
[10] Leibniz Inst Astrophys, D-14482 Potsdam, Germany
[11] Nicolaus Copernicus Astron Ctr, PL-00716 Warsaw, Poland
[12] Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile
[13] Vatican Observ, I-00120 Vatican City, Vatican
[14] Ohio State Univ, Columbus, OH 43210 USA