1. Univ. of Notre Dame (United States)
2. Univ. of Cambridge (United States)
3. Large Binocular Telescope Observatory (United States)
4. Steward Observatory, The Univ. of Arizona (United States)
5. Harvard-Smithsonian Ctr. for Astrophysics (United States)
6. NASA Goddard Space Flight Ctr. (United States)
7. Jet Propulsion Lab. (United States)
8. The Univ. of Arizona (United States)
9. The Ohio State Univ. (United States)
10. The Pennsylvania State Univ. (United States)
11. INAF - Osservatorio Astronomico di Palermo (Italy)
12. Univ. of Virginia (United States)
13. INAF - Osservatorio Astrofisico di Catania (Italy)
14. Landessternwarte Heidelberg (Germany)
15. Macquarie Univ. (Australia)
16. INAF - Osservatorio Astrofisico di Torino (United States)
17. Univ. of Minnesota (United States)
18. Univ. of Florida (United States)