1. Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Pune 411007, India
2. INAF/Osservatorio Astrofisico di Torino, Strada Osservatorio 20, I-10025 Pino Torinese, Italy
3. Dipartimento di Fisica Generale, Universita degli Studi di Torino, Via Pietro Giuria 1, I-10125 Torino, Italy
4. Discipline of Astronomy, Astrophysics and Space Engineering, Indian Institute of Technology Indore, Khandwa Road, Simrol 453552, India