Institution: | 1University of Southampton, Department of Physics &Astronomy, Highfield, Southampton, S017 1BJ; 2Department of Physics, Keele University, Staffordshire, ST5 5BG; 3Dr. Remeis-Sternwarte, Astronomisches Institut der Universität Erlangen-Nürnberg, Sternwartstrasse 7, 96049 Bamberg, Germany |