Institution: | (1) Netherlands Foundation for Research in Astronomy, Dwingeloo;(2) Free University, Amsterdam, The Netherlands;(3) Astrophysical Institute of the Free University at Brussels, VUB;(4) Sterrewacht Leiden;(5) Kapteyn Observatory at Roden, The Netherlands;(6) Institute of Physics of the Earth at Moscow, Moscow, Russia;(7) Astronomical Institutes of the University at Bonn, Bonn, Germany |