1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.
2. Lick Observatory, University of California Observatories, University of California, Santa Cruz, CA 95064, USA.
3. Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen, Denmark.
4. NASA Ames Research Center, Moffett Field, CA 94035, USA.
5. SETI Institute, Mountain View, CA 94043, USA.
6. University of Texas, Austin, TX 78712, USA.
7. University of Florida, Gainesville, FL 32611, USA.
8. Stanford University, Stanford, CA 94305, USA.
9. Orbital Sciences Corp., Dulles, VA 20166, USA.
10. San Diego State University, San Diego, CA 92182, USA.
11. Fermilab Center for Particle Astrophysics, Batavia, IL 60510, USA.