1. 1. Department of Astronomy, University of Cape Town, Rondebosch, South Africa (makwela@mpia-hd.mpg.de). 2. International Astronomical Union, Office of Astronomy for Education, Haus der Astronomie, Max Planck Institut für Astronomie, Knigstuh 17, D-69117 Heidelberg, Germany.
2. 1. Department of Physics, University of Cape Town, Rondebosch, South Africa. 2. Academic Development Programme, University of Cape Town, South Africa.
3. Department of Astronomy, University of Cape Town, Rondebosch, South Africa.