1. Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
2. Department of Physics and Astronomy, University of the Western Cape, Modderdam Road, Private Bag X17, Belville 7530, South Africa
3. Inter-University Institute for Data Intensive Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa