1. Instituto de Astronomia, Geofísica e Ciencias Atmosféricas, University of São Paulo, R. do Matão 1226, 05508-090 São Paulo, Brazil
2. Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA, Leiden, The Netherlands
3. National Centre for Nuclear Research, Astrophysics Division, P.O. Box 447, PL-90-950 Lodz, Poland
4. INAF - Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
5. INAF - Osservatorio Astronomico di Padova, via dell’Osservatorio 5, 35122 Padova, Italy