1. Department of Physics, University of Alberta, CCIS 4-181, Edmonton, AB T6G 2E1, Canada
2. Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA
3. Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
4. INAF - Osservatorio astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (LC), Italy
5. Department of Astronomy, Indiana University, 727 E. Third Street, Bloomington, IN 47405, USA
6. Department of Physics and Astronomy, Haverford College, 370 Lancaster Ave, Haverford, PA 19041, USA
7. Mathematical Sciences, Physics & Astronomy and STAG Research Centre, University of Southampton, Southampton SO17 1BJ, UK
8. LUTH, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, F-92190 Meudon, France