1. Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
2. Finnish Centre for Astronomy with ESO (FINCA), University of Turku, FI-20014 Turku, Finland
3. INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (PD), Italy
4. Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monteporzio Catone, Italy
5. IASF Milano, via Corti 12, I-20133 Milano, Italy
6. Instituto de Astrofisica de Canarias, C/O Via Lactea, s/n, E-38205 La Laguna (Tenerife), Spain
7. Dpto. Astrofsica, Universidad de La Laguna, s/n, E-38206, La Laguna (Tenerife), Spain