1. Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
2. European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
3. Laboratory of Observational Astrophysics, Saint Petersburg State University, Universitetsky pr. 28, 198504 Saint Petersburg, Russia
4. Laboratório Nacional de Astrofísica /MCTIC, Rua Estados Unidos, 154, CEP 37504-364, Itajubá, MG, Brazil
5. Central Astronomical Observatory at Pulkovo, Pulkovskoye chaussee 65, 196140 Saint Petersburg, Russia