1. Department of Physics & Astronomy, University of California , Irvine, 4129 Reines Hall, Irvine, CA 92697 , USA
2. Department of Physics and Astronomy, University of Waterloo , Waterloo, ON N2L 3G1 , Canada
3. Waterloo Centre for Astrophysics, University of Waterloo , Waterloo, ON N2L 3G1 , Canada
4. Department of Physics & Astronomy, University of Kansas , 1251 Wescoe Hall Drive, Malott room 1082, Lawrence, KS 66045 , USA
5. INAF - Osservatorio Astronomico di Trieste , via G.B. Tiepolo 11, I-34143 Trieste , Italy
6. Departamento de Astronomía, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción , Concepción , Chile
7. Department of Physics, University of Helsinki , Gustaf Hällströmin katu 2a, FI-00014 Helsinki , Finland
8. Department of Physics and Astronomy, University of California Davis , One Shields Avenue, Davis, CA 95616 , USA
9. Department of Physics and Astronomy, York University , 4700 Keele St., Toronto, Ontario, M3J 1P3 , Canada
10. IRAP, Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, UPS-OMP, CNRS, CNES , 14 avenue E. Belin, F-31400 Toulouse , France
11. INAF - Osservatorio astronomico di Padova , Vicolo Osservatorio 5, I-35122 Padova , Italy
12. Department of Physics & Astronomy, University of California , Riverside, 900 University Avenue, Riverside, CA 92521 , USA
13. Steward Observatory and Department of Astronomy , 933 N. Cherry Ave, University of Arizona, Tucson, AZ 85721 , USA