Near-Infrared Observations of S 255-2 : The Heart of a Massive YSO Cluster

High-resolution near-infrared ( JHKLM � ) images of a massive star-forming region, S 255-2, were obtained with the Subaru Telescope and an infrared camera, CIAO. These images clearly resolve two sets of bipolar nebulae illuminated by two independent massive YSOs. A number of cluster member YSOs have been detected, including 3 new sources. Seven early-B type stars have been identified within 10pc of S 255-2; three are associated with extended optical H II regions. The variation in the appearance of these early-B type stars suggests an evolutionary sequence of massive stars in the S 255 region.