An optical and infrared study of the reflection nebulae GGD-30 and GGD-31

Abstract

CCD images and near-IR observations of the nebular objects GGD 30 and GGD 31 are presented. The data have been used to study the morphology and physical nature of the nebulosities. GGD 30 is a reflection nebula illuminated by a low mass PMS star of estimated luminosity almost-equal-to 2.3 L.. The CCD images reveal that the illuminating star is likely to be double with a separation between components of 4", corresponding to a projected linear separation of 2000 AU. A stream arises from one of the stellar components; our data do not show, however, evidence of shock-excited material. GGD 31 is a reflection nebula showing a rather complex morphology. It has a dark cavity within the nebulosity and there are two nebular streams arising from the illuminating star and surrounding the cavity. The estimated luminosity of the star is almost-equal-to 10 L.. In addition, the region around GGD 30 has been surveyed in the near-IR and also searched for IRAS point sources. A further PMS object is present in the GGD 30 region. Finally, a peculiar near-IR object has been detected. The object seems to be a late type oxygen-rich star with very extreme colours, H - K = 4.47, K - L' = 4.49, and L' - M' = 1.19 mag.