JCMT OBSERVATIONS OF THE IONIZING STARS IN THE H-II-REGION-W40

Continuum observations of the main ionizing stars OS1a, OS2a, and OS3a in the H II region/molecular cloud W40 were made with the James Clerk Maxwell Telescope in Hawaii, in August 1991, January 1992, and June 1 993. OS1a was detected at a level of 56+/-18 mJy at 1.1 mm wavelength. OS2a was detected with a mean of 265+/-6 mJy at 1.1 mm, and at 654+/- 160 mJy at 0.8 mm. OS3a was not detected at 1.1 mm. These mm-submm obs ervations imply the existence of substantial circumstellar material ar ound the main ionizing star OS2a (similar to 0.1.M circle dot), and a smaller amount around OS1a (similar to-0.02M circle dot). Only an uppe r limit is inferred for OS3a.