1. Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia
2. Department of Astronomy & Space Sciences, Erciyes University, 38039, Kayseri, Turkey
3. Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg, Germany
4. Astrophysics Group, Keele University, Staffordshire ST5 5BG, UK
5. Jeremiah Horrocks Institute, University of Central Lancashire, Preston, Lancashire PR1 2HE, UK