The first black astrophysicist in South Africa obtained his doctorate in May from the University of Potchefstroom.
Dr Rocky Sefako, a lecturer in Potch’s School of Physics, matriculated with distinction at the Khukhune High School in Botha-Bothe. In 1995 he obtained the BSc degree at the National University of Lesotho, and completed his MSc at Potch in 1998. His MSc dissertation led to a publication in the Monthly Notices of the Royal Astronomical Society.
His doctoral dissertation, A Study of Selected Southern Sky Synchro-Compton Sources, examined two types of cosmic sources of high-energy emitters, namely a class of Active Galactic Nucleuses, where a million-solar-mass black hole accretes interstellar gas, matter, stars and their planets, resulting in all matter being pressed into a singular point.
The rotation energy of this whirlpool-motion around the black hole is then cancelled into two very narrow beams that jet out perpendicularly on both sides of the whirlpool. If such a jet is directed towards the Earth, the energy in the jet will be visible as radio waves, visible light, X-rays and gamma waves.
Sefako was the first to observe cyclic colour changes in such a jet in the optical area, by means of Sutherland’s telescopes.
Each cycle represents the collapse of another star, its possible planets or a big gas cloud in the black hole. This data enables us to model the acceleration of very high-energy electrons and protons in the two jets.
He also observed the environments of rapidly spinning neutron stars by means of the same telescopes.