Siding Spring Observatory, NSW, Australia (visiting astronomer, 2007), Hungarian Astronomical Association's Polaris Observatory, Budapest, (from 2006 - ) Baja Astronomical Observatory (visiting astronomer, 2005) The German-Spanish Astronomical Center at Calar Alto Observatory (visiting astronomer, 2000 and 2001) Observatory of Hungarian Scientific Academy Konkoly-Thege Miklós Astronomical Research Institute at Piszkéstetõ, Hungary (visiting astronomer from 1997) Observatory of Szeged (from 1996)