1. Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune-411007, India
2. Mody College of Engineering and Technology, Lakshmangarh, 332311, India
3. Indian Institute of Astrophysics, Koramangala, Bangalore 560034, India
4. Max Planck Institut fur Astrophysik, 85740 Garching, Germany