[1] Univ Geneva, DPNC, 24 Quai Ernest Ansermet, Geneva, Switzerland
[2] Univ Geneva, Dept Astron, 16 Chemin Ecogia, Geneva, Switzerland
[3] H Niewodniczanskiego Polskiej Akad Nauk, Inst Fizyki Jadrowej, Ul Radzikowskiego 152, PL-31342 Krakow, Poland
[4] Univ Warsaw, Astron Observ, Al Ujazdowskie 4, PL-00478 Warsaw, Poland
[5] Jagellonian Univ, Astron Observ, Ul Orla 171, PL-30244 Krakow, Poland
[6] Polskiej Akad Nauk, Ctr Badan Kosmicznych, Warsaw, Poland
[7] Polish Acad Sci, Nicolaus Copernicus Astron Ctr, Warsaw, Poland
[8] Taras Shevchenko Natl Univ Kyiv, Astron Observ, Observ Str 3, Kiev, Ukraine
[9] AGH Univ Sci & Technol, Al Mickiewicza 30, Krakow, Poland
[10] Czech Acad Sci, Inst Phys, 17 Listopadu 50,Olomouc & Na Slovance 2, Prague, Czech Republic
[11] Jagiellonian Univ, Dept Informat Technol, Ul Prof Stanislawa Lojasiewicza 11, PL-30348 Krakow, Poland
[12] Univ Libre Bruxelles, Fac Sci, Ave Franklin Roosevelt 50, B-1050 Brussels, Belgium