INFRARED AND OPTICAL IMAGING OF NEWBORN STARS

Broadband infrared (J, H, K) and optical (r, i, z) images of five low-to intermediate-luminosity premain-sequence stars and infrared imaging polarimetry for 04016 + 2610 and 16316 - 1540 are presented. All sources are moderately to heavily obscured (10 < Av < 30) and are located in regions characterized by high gas densities (104-105 cm-3). Four of the five stars have been previously identified as outflow sources. Nebulosity is detected within the optical and J and H bandpasses for each source and, in the cases of 03445 + 3242, 04016 + 2610, 05380 - 0728, and 16316 - 1540, is projected upon the blueshifted lobe of high-velocity CO emission. The large measured polarization values (p = 10% to 70%) at H and K identify this nebulosity as scattered light. At K the intensity distribution is generally less extended than at J and H, and is characterized by an additional, unresolved component. The position of this point source likely identifies the location of the newborn star within the field. For all sources, the illuminating star is redder than its associated nebula. The proximity of a reddened star and scattered optical light in regions with large visual extinctions suggest a nonspherical distribution of circumstellar material with both high- and low-opacity paths from the star. The observed correlation of cometary reflection nebulae with newborn stars undergoing mass outflow suggests that the low-opacity paths are cavities associated with energetic stellar winds.