On leave of absence from the CNRS, Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse

  Current address: 
     	   Prof. Daniel Schaerer
     	   Observatoire de Genève
           Université de Genève
	   51, Ch. des Maillettes
	   CH-1290 Versoix
	   Switzerland
  Phone:   +41 22 379 24 54 (direct line) - 022 379 24 54 (within Switzerland)
  Fax:     +41 22 379 22 05               - 022 379 22 05 (within Switzerland)

  e-mail:  daniel.schaerer@unige.ch (old address with obs.unige.ch not valid anymore!)