Optical CCD imaging of some Herbig Ae/Be stars

Abstract

Results of V, R, and H-alpha CCD imaging for 15 Herbig Ae/Be stars are presented. Light variations of more than about 2 mag in V have been noticed in stars T Ori, RR Tau, and LH-alpha 25. The nature of the variations in brightness and color indicates that changes in the distribution of the circumstellar material around the stars could be the reason for the variability. For most of the objects, the observed radial variation of the surface brightness in different filters can be understood in terms of the light scattered by dust particles in the surrounding nebula with radially decreasing dust density. A bright emission knot located about 14 arcsec north and 7 arcsec east of R Mon is found to be inexplicable in terms of scattering of central star light by nebular dust.