1. South African Astronomical Observatory, PO Box 9, Observatory 7935, Cape Town, South Africa
2. Department of Astronomy, University of Cape Town, Private Bag, Rondebosch 7700, Cape Town, South Africa
3. Southern African Large Telescope, PO Box 9, Observatory 7935, Cape Town, South Africa
4. Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisälantie 20, FI-21500 Piikkiö, Finland
5. Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755, USA
6. Special Astrophysical Observatory of RAS, Nizhnij Arkhyz, Karachai-Circassia 369167, Russia
7. M.V. Lomonosov Moscow State University, Physics Department, Leninskie gory, GSP-1, Moscow 119991, Russia
8. M.V. Lomonosov Moscow State University, Sternberg Astronomical Institute, Universitetsky pr., 13, Moscow 119234, Russia