1. Positional Astronomy Centre, Block - AQ, Plot - 8, Sector V, Salt Lake City, Kolkata 700091, India
2. Department of Applied Optics and Photonics, University College of Science and Technology, University of Calcutta, JD - 2, Sector - III, Salt Lake, Kolkata 700098, India
3. Department of Mathematics, Hiralal Mazumdar, Memorial College for Women, Dakshineswar, Kolkata 700035, India
4. Physics and Applied Mathematics Unit, Indian Statistical, Institute, 203, B.T. Road, Kolkata 700108, India