SRON Laboratory for Space Research at Utrecht, Utrecht, The Netherlands
R. Mewe & K. A. van der Hucht
Laboratory for Space Research at Utrecht, Utrecht, The Netherlands
Cornelis de Jager
Astronomical Institute, Ondřejov
J. Kleczek
Sterrewacht Leiden, Leiden, The Netherlands
Vincent Icke
The Astronomical Institute at Utrecht, Utrecht, The Netherlands
H. G. van Bueren
Harvard Smithsonian Center for Astrophysics at Cambridge, USA
C. Jones
Paris Observatory, Meudon
E. Schatzman
Geneva Observatory at Sauverny, Sauverny, Switzerland
G. Meynet
Kapteyn Astronomical Institute at Groningen, Groningen, The Netherlands
P. C. van der Kruit
Alfvén Laboratory, Royal Institute of Technology, Stockholm
M. A. Raadu
University of Brussels (VUB), Brussels
C. Sterken