[1] Armagh Observ & Planetarium, Coll Hill, Armagh BT61 9DG, North Ireland
[2] V N Karazin Kharkiv Natl Univ, Inst Astron, 35 Sumska str, UA-61022 Kharkiv, Ukraine
[3] INAF Osservatorio Astrofisico Torino, I-10025 Turin, Italy
[4] CALTECH, Infrared Proc & Anal Ctr IPAC, 1200 Calif Blvd, MC 100-22, Pasadena, CA 91125 USA
[5] CSIC, Inst Astrofis Andalucia, Glorieta Astron S-N, Granada 18008, Spain
[6] Leiden Observ, Einsteinweg 55, NL-2333 CC Leiden, Netherlands