1. Univ. de Liège (Belgium)
2. California Institute of Technology (United States)
3. Uppsala Univ. (Sweden)
4. Cornell Univ. (United States)
5. W. M. Keck Observatory (United States)
6. European Southern Observatory (Chile)
7. Steward Observatory, The Univ. of Arizona (United States)
8. Lab. AIM, CEA, Univ. Paris Diderot, IRFU (France)
9. Uppsala Univ. (Sweden)
10. Jet Propulsion Lab. (United States)