1. Indian Institute of Astrophysics, II Block, Koramangala, Bengaluru 560 034, India
2. National Astronomical Observatories, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing 100101, P. R. China
3. Joint Astronomy Programme, Department of Physics, Indian Institute of Science, Bengaluru 560 012, India
4. Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
5. Okayama Observatory, Graduate School of Science, Kyoto University, 3037-5 Honjo, Kamogata, Asakuchi, Okayama 719-0232, Japan
6. Department of Physical Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526, Japan
7. Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263 001, India