The bipolar nebula S106 - Photometric, polarimetric, and spectropolarimetric observations

Multicolor photometry, photopolarimetry and spectropolarimetry is presented for the bipolar nebula S 106, a compact H II region associated with a massive molecular cloud, and for field stars projected on it. UVBRI photometry and broadband polarimetry of field stars is used to derive a foreground extinction and polarization which yields a distance to the molecular complex of 600 + or - 100 pc. Photopolarimetry of the nebular lobes in the optical and IR regions indicates the polarization vectors to be nearly perpendicular to the radius vector to the point source identified as the single stellar source, which is apparently due to grain alignment in the equatorial dust lane. Spectrophotometry of the brightest knot in the southern lobe of the nebula, reveals emission lines typical of a radiatively excited H II region, and indicates a portion of the line flux to be reflected radiation from the central star, identified as spectral type O9 V.