Near-infrared and Stromgren photometry of the open clusters NGC 663, NGC 1502 and NGC 1893*

Abstract

Near-infrared JHK, and Stromgren uvby and Hβ photometry of the central parts of three open clusters, NGC 663, NGC 1502 and NGC 1893, are presented. The following results were derived from the data : NGC 663 is at a distance of 2.5 kpc (m−M=12.03±0.20) and is obscured by A v =1.98±0.04, its age is 9×10 6 yr; NGC 1502 is at a distance of 1.5 kpc (m−M=10.84±0.10) and is obscured by A v =1.83±0.03, its age is 5×10 6 yr; NGC 1893 is at a distance of 4.3 kpc (m−M=13.18±0.11) and is obscured by A v =1.68±0.06, its age is 4×10 6 yr.