A multiwavelength study of the ultracompact HII region associated with IRAS 20178+4046

Aims. We present a multiwavelength study of the ultra compact HII region associated with IRAS 20178+4046. This enables us to probe the different components associated with this massive star-forming region. Methods. The radio emission from the ionized gas was mapped at 610 and 1280 MHz using the Giant Metrewave Radio Telescope (GMRT), India. We used 2MASS JHKs data to study the nature of the embedded sources associated with IRAS 20178+4046. Submillimetre emission from the cold dust at 450 and 850 µm was studied using JCMT-SCUBA. Results. The high-resolution radio continuum maps at 610 and 1280 MHz display compact spherical morphology. The spectral type of the exciting source is estimated to be ∼B0.5 from the radio flux densities. However, the near-infrared data suggest the presence of several massive stars (spectral type earlier than O9) within the compact ionized region. Submillimetre emission shows two dense