[1] European Space Agcy, European Space Res & Technol Ctr, Keplerlaan 1, NL-2200 AG Noordwijk, Netherlands
[2] Space Telescope Sci Inst, Baltimore, MD 21218 USA
[3] Osserv Astron Capodimonte, INAF NA, I-80131 Naples, Italy
[4] Supernova Ltd, Virgin Gorda VG1150, Virgin Islands, Iceland
[5] Smithsonian Astrophys Observ, Cambridge, MA 02138 USA
[6] Univ Palermo, Dipartimento Fis & Chim, I-90134 Palermo, Italy
[7] Osserv Astron Palermo, INAF PA, I-90134 Palermo, Italy