Institution: | Institute of Astronomy &Astrophysics, National Observatory of Athens, I. Metaxa &B. Pavlou, Penteli, 15236, Athens, Greece;Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH;Physics Department, University of Durham, Science Laboratories, South Road, Durham DH1 3LE;Anglo-Australian Observatory, PO Box 296, Epping, NSW 2121, Australia |