1. Department of Physics and Astronomy, University of North Carolina at Greensboro, Greensboro, NC 27402, USA
2. CFHT Corporation, 65-1238 Mamalahoa Highway, Kamuela, HI 96743, USA
3. Instituto de Astronomía, Universidad Nacional Autónoma de México, Apartado Postal 877, 22830 Ensenada, BC, Mexico
4. Departimento de Físika, Escuela Superior de Física y Matematicas del Instituto Politecnico Nacional, Edif. 9, U. P. Zacatenco, 07738 Cuidad de Mexico, DF, Mexico
5. Geneva Observatory, Geneva University, Chemin des Maillettes 51, 1290 Sauverny, Switzerland
6. Instituto de Ciencias Astronómicas de la Tierra y del Espacio, CONICET, Casilla de Correo 49, 5400 San Juan, Argentina
7. The Aerospace Corporation, M2/266, P.O. Box 92957, Los Angeles, CA 90009, USA
8. Center for Astrophysics and Space Science, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
9. Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599, USA