This is a picture of a location where a cluster of massive stars being born. W3 Main is a star forming region in the constellation Cassiopeia. Young massive stars, similar to those found in Trapezium in the constellation Orion, are crowded together in the region shown in red near the center of the image. Multiple OB type stars exist in that region. They illuminate the remnants of the gas and dust which birthed these stars, forming bright nebulae interlaced with dark nebulae in an intricate pattern. In this manner, W3 Main is a region where many massive stars are being born. But these observations discovered that many brown dwarfs, small objects with too little mass to become stars, are also forming. The discovery of stealthy brown dwarfs within an active star forming region shows the power of the Subaru Telescope’s high sensitivity and high resolution.

Author: Miki Ishii (TMT-Japan)