1. Department of Physics, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL , UK
2. Center for Data Intensive and Time Domain Astronomy, Department of Physics and Astronomy, Michigan State University , East Lansing, MI 48824 , USA
3. Department of Physics & Astronomy, Wayne State University, 666 W Hancock St, Detroit, MI 48201 , USA
4. Norfolk State University , 700 Park Avenue, Norfolk, VA 23504 USA
5. Department of Physics & Astronomy, Texas Tech University , Box 41051, Lubbock, TX 79409-1051 , USA
6. Department of Physics and Astronomy, University of California , Los Angeles, CA 90095 , USA
7. Department of Astronomy, California Institute of Technology , 1200 E. California Blvd, Pasadena, CA 91125 , USA
8. Institute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA , UK
9. Departament de Física, Universitat Politècnica de Catalunya , c/Esteve Terrades 5, 08860 Castelldefels , Spain
10. Department of Physics and Astronomy, Hicks Building, The University of Sheffield , Sheffield S3 7RH , UK
11. Instituto de Astrofísica de Canarias (IAC) , E-38205 La Laguna, Tenerife , Spain
12. Max – Planck – Institut für Astronomie , Königstuhl 17, D-69117 Heidelberg , Germany
13. Department of Astrophysics, School of Physics and Astronomy, Tel Aviv University , Tel Aviv 6997801 , Israel
14. Department of Physics, University College Cork , Cork , Ireland
15. Isaac Newton Group of Telescopes , Apartado de Correos 321, Santa Cruz de La Palma E-38700 , Spain