Staff Members

Home » Prof. Hartmut Winkler
Prof Hartmut Winkler

Name: Hartmut Winkler
Location: C1 Lab 241 Auckland Park Kingsway Campus
Physics Academic Staff  Staff Members

Contact Details:
Tel: 011 559 4417


About Prof. Hartmut Winkler

For more detailed information, please visit Hartmut Winkler’s Personal web page:


Authored or co-authored articles:

  •     60 articles in scientific journals (52 subsidised & peer reviewed; 17 as first author)
  •     50 articles in conference proceedings. Click HERE to view the list and access the articles
  •     Presented nine oral and five poster papers at international conferences
  •     Numerous scientific talks, including sixteen overseas

NRF Rating: C2


  •     Matsumae International Foundation Fellowship – Apr-Sep 1996
  •     DAAD Research Grant – May-Jul 2011


Prof Winkler’s scientific work is split between two foci of interest:

  1. Atmospheric Physics and Energy: Solar irradiation, aerosols, interaction between radiation and aerosols, solar energy, the South African energy landscape
    Prof Winkler is developing higher-accuracy models to quantify (on a site-specific basis) the solar radiation collected by a range of solar power technologies, including photovoltaic panels and parabolic troughs. In particular these models consider the impact of aerosols and atmospheric pressure profiles on the light path, attenuation and scattering, leading to improved, light wavelength-specific insolation parameters. Model parameters are in most cases expressly tailored to describe the conditions at South African sites, and thus provide site diagnostics for potential solar power station developments. The same physics also translates to astronomical sky brightness calculations, and has been used to develop a night sky characterisation at the South African Astronomical Observatory. Prof Winkler has also a well-known commentator on energy scenarios South Africa, especially in the debate of renewable energy versus nuclear.
  2. Astrophysics: Active Galactic Nuclei (AGN), in particular Seyfert galaxies – spectral properties, classification, variability, optical photometry
    Prof Winkler devised and developed the flux variation gradient method for determining the obscuration and intrinsic luminosity of Seyfert nuclei. He has also been engaged and published in a multitude of projects in different branches of astronomy, including the determination of intrinsic infrared colours of B-stars, an analysis of the spectra of B[e] stars, the large scale structure of the universe, several novae, supernova 1987a, symbiotic stars and cataclysmic variables. He has been part of several recent international AGN reverberation mapping campaigns, X-ray source identification and searches for “changing look” AGN. He has developed (and is continuously updating) the ZAC database of AGN optical spectra and luminosities, and devising a more sophisticated spectral classification system for AGN.

Click here to access the ZAC webpage


1992: “Variability studies of Seyfert galaxies. I Broad band optical photometry”, Winkler H, Glass IS, Van Wyk F, Marang F, Spencer Jones JH, Buckley DAH, Sekiguchi K, Monthly Notices Roy. Astron. Soc. 257, 659-676 (96 citations)

1992: “Variability studies of Seyfert galaxies. II Spectroscopy”, Winkler H, Monthly Notices Roy. Astron. Soc. 257, 677-688 (142 citations)

1997: “Red and infrared colours of B-stars and the reddening law in the Galaxy”, Winkler H, Monthly Notices Roy. Astron. Soc., 287, 481-494 (64 citations)

1997: “The extinction, flux distribution and luminosity of Seyfert 1 nuclei derived from UBV(RI)c aperture photometry”, Winkler H, Monthly Notices Roy. Astron. Soc., 292, 273-288 (48 citations)

2022: “A revised simplified scattering model for the moonlit sky brightness profile based on the photometry at SAAO”, Monthly Notices Roy. Astron. Soc. 514, 208-226 (2 citations)

Publications And Other Research Outputs