1. Department of Physics, United Arab Emirates University, Al-Ain, UAE, 15551
2. Academia Sinica Institute of Astronomy and Astrophysics, Taipei 10617, Taiwan
3. Armagh Observatory and Planetarium, College Hill, Armagh BT61 9DG, UK
4. School of Physics, Trinity College Dublin, College Green, Dublin 2, Ireland
5. Physics Department, University of Nebraska at Omaha, 6001 Dodge St, Omaha, NE, 68182, USA