[1] LAEX-CAB (INTA-CSIC), LAEFF, PO Box 78, 28691 Villanueva de la Cañada, Madrid, Spain
[2] Depto. de Física, Universidade Federal de Minas Gerais, C.P.702, 30161-970 - Belo Horizonte, MG, Brazil
[3] Laboratório Nacional de Astrofísica/MCT, Rua Estados Unidos 154, 37504-364 Itajubá, Brazil
[4] Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, QC H3C 3J7, Canada
[5] European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei Muenchen, Germany
[6] European Southern Observatory, Alonso de Cordova 3107, Casilla 19, Santiago, Chile
[7] Laboratoire d'Astrophysique, Observatoire de Grenoble, BP 53, 38041 Grenoble, Cedex 9, France
[8] Instituto de Astrofísica de Canarias, C Vía Láctea, s/n, E38205 - La Laguna (Tenerife), Spain