1. Department of Physics, Cotton University , Panbazar, Guwahati 781001, Assam, India
2. Department of Physics, State University of New York Oswego , Oswego, NY 13126, USA
3. Space and Astronomy Research Center, Cotton University , Panbazar, Guwahati 781001, Assam, India
4. Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), Konkoly Thege Miklós út 15-17, H-1121, Budapest, Hungary
5. Max Planck Institute for Astrophysics , Garching Karl-Schwarzschild-Str. 1, Postfach 1317, D-85741 Garching, Germany
6. Department of Physics and Astronomy, Aarhus University, , Ny Munkegade 120, DK-8000 Aarhus, Denmark
7. INAF-Osservatorio Astronomico di Capodimonte , Via Moiariello 16, I-801301 Napoli, Italy