1. Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada
2. Argelander-Institut für Astronomie (AIfA), Universität Bonn, Auf dem Hügel 71, D-53121 Bonn, Germany
3. Department of Physics and Astronomy, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
4. Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario M5S 3H4, Canada
5. Department of Physics and Astronomy, University of California-Riverside, 900 University Avenue, Riverside, CA 92521, USA