1. Apache Point Observatory and New Mexico State University , Sunspot, NM 88349, USA
2. Sternberg Astronomical Institute, Moscow State University , Universitetskiy prosp. 13, Moscow 119234, Russia
3. Special Astrophysical Observatory of the Russian AS , Nizhnij Arkhyz 369167, Russia
4. New Mexico State University , Last Cruces, NM 88003, USA
5. School of Astronomy and Space Science, Nanjing University , Nanjing 210093, China
6. Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education , Nanjing 210093, China
7. McDonald Observatory, The University of Texas at Austin , 1 University Station, Austin, TX 78712, USA
8. Centro de Investigacíon en Astronomía, Universidad Bernardo O’Higgins , Avenida Viel 1497, Santiago, Chile
9. Department of Physics and Astronomy, University of Utah , 115 S. 1400 E., Salt Lake City, UT 84112, USA
10. Departamento de Física, CCNE, Universidade Federal de Santa Maria , Santa Maria, RS 97105-900, Brazil
11. Laboratório Interinstitucional de e-Astronomia - LIneA , Rua Gal. José Cristino 77, Rio de Janeiro, RJ - 20921-400, Brazil