Institution: | Institut für Astronomie, Universität Wien, Türkenschanzstraße 17, A-1180 Wien, Austria;South African Astronomical Observatory, PO Box 9, Observatory 7935, South Africa;Visiting Fellow, Australian National University, Canberra, ACT, Australia;Department of Physics, University of the North-West, Private Bag X2046, Mmabatho 2735, South Africa |