Institution: | Osservatorio Astrofisico di Catania, CittáUniversitaria, Via Santa Sofia 78, 95123 Catania, Italy; Institute of Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ; SRON, 3584 CA Utrecht, the Netherlands; Department of Astronomy and Astrophysics, Centre for Astrophysics and Space Science, Chalmers University of Technology, SE-43992 Onsala, Sweden; Osservatorio Astronomico di Roma, Monteporzio Catone, Italy; Liceo Scientifico Statale 'E. Majorana', Scordia, Italy |