¹ Department of Astronomy, University of Michigan, 830 Dennison Building, Ann Arbor, MI 48109
² Department of Physics, University of Michigan, 500 East University, Ann Arbor, MI 48109
³ Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260
⁴ Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510
⁵ Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637
⁶ Department of Physics and Astronomy, Johns Hopkins University, 3701 San Martin Drive, Baltimore, MD 21218
⁷ Princeton University Observatory, Princeton, NJ 08544
⁸ Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349-0059
⁹ Department of Physics of Complex Systems, Eötvös University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
¹⁰ US Naval Observatory, 3450 Massachusetts Avenue NW, Washington, DC 20392-5420
¹¹ Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101
¹² Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195
¹³ US Naval Observatory, Flagstaff Station, P.O. Box 1149, Flagstaff, AZ 86002-1149
¹⁴ Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180
¹⁵ Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802
¹⁶ Department of Physics, Drexel University, Philadelphia, PA 19104
¹⁷ Department of Astronomy, Ohio State University, 174 West 18th Avenue, Columbus, OH 43210
¹⁸ Current address: Department of Astronomy, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8, Canada