1. Dark Sky Consulting, LLC , PMB 237, 9420 E Golf Links Rd Ste 108, Tucson, AZ 85730-1317, USA
2. ICA, Slovak Academy of Sciences , Dúbravská cesta 9, 845 03 Bratislava , Slovakia
3. Department of Astrophysics, University of Vienna , Tuerkenschanzstrasse 17, A-1180 Wien , Austria
4. Department of Experimental Physics, FMPI, Comenius University , Mlynská dolina, 842 48 Bratislava , Slovakia