Near-infrared imaging polarimetry of bipolar nebulae: Pt. 3

High-spatial-resolution polarization and surface brightness images of R Mon/NGC 2261 at J, H and K are presented. The polarmetric images show that NGC 2261 is a near reflection nebulae, illuminated by R Mon. there is evidence that R Mon is surrounded by a dense disc or toroid of material. This evidence includes the constancy and direction of the polarization position angle with wavelength, the low polarization observed immediately to the east and west of R Mon, and the increasing blueness of NGC 2261 with increasing angular distance from R Mon. NGC 2261 shows increasing polarization from H to K, which is most likely due to the presence of grains with a size distribution larger than that found in the diffuse ISM. (author)