| Institution: | Institute of Astronomy &Astrophysics, National Observatory of Athens, I. Metaxa &V. Pavlou, Athens 15236, Greece;Astrophysics Group, Blackett Laboratory, Imperial College, Prince Consort Rd, London SW7 2BZ;Instituto Nacional de Astrofísica Óptica y Electrónica, AP 51 y 216, 72000 Puebla, Pue, México;Instituto de Astronomia, Universidad Nacional Autonoma de México, A.P. 70-264, DF 04510, México;Astronomical Laboratory, Department of Physics, University of Patras, 26500 Rio-Patras, Greece |
