1. Institute of Cosmology and Gravitation, University of Portsmouth, Burnaby Road, Portsmouth PO1 3FX, UK
2. Departamento de Astronomía, Casilla 160-C, Universidad de Concepción, Concepción, Chile
3. Institut Utinam, CNRS UMR6213, University Bourgogne Franche-Comté, OSU THETA, Observatoire de Besançon, BP 1615, F-25010 Besançon Cedex, France
4. Department of Physics & Astronomy - Universidad de La Serena - Av. Juan Cisternas, 1200 North, La Serena, Chile
5. Chinese Academy of Sciences,National Astronomical Observatories of China, 20A Datun Road, Chaoyang District, Beijing 100012, China
6. Department of Physics and Astronomy, University of Kentucky, 505 Rose Street, Lexington, KY 40506-0055, USA