THE ACTIVE SOURCE IN THE REGION OF THE HERBIG STAR BD-DEGREES-4124(40)

We present new near-infrared, millimeter and radio observations of the region associated with BD +40 degrees 4124, a Herbig Be star located in the direction of the Cygnus arm. BD +40 degrees 4124 is the optical ly brightest member of a small group of young emission line stars, inc luding V 1318 Cygni and V 1686 Cygni. Near-IR broad-band imaging of V 1318 Cygni reveals the presence of two distinct stellar components ori ented north-south, a result recently reported by Aspin et al. (1994). On a larger scale, the near-IR images also indicate the presence of ma ny highly embedded sources concentrated in the vicinity of the bright visible stars. In the central part of the cluster, the near-IR sources outnumber the optically visible ones by a factor of three. The distri bution of the high density molecular gas traced by the CS J=5-->4 emis sion is highly concentrated around V1318 and V1686 Cygni, while the to tal column density of gas traced by the (CO)-O-18 J=2-->1 shows a ridg e morphology centered on these sources. The Herbig star BD +40 degrees 4124 lies at the edge of both structures. From the otpically thin (CO )-O-18 emission, we derive a total molecular mass of M(core)=280 M.. A molecular outflow has been detected in CO J=2-->1. The high velocity gas is confined to a compact region of size approximate to 20'', corre sponding to a physical length of 0.1 pc. The outflow is not well resol ved, or collimated, on the observed scales. We have also detected H2O maser emission at 22.2 GHz at a position coincident with the center of the bipolar outflow. Both the maser and the outflow are located at th e position of the southern source V 1318 S which we identify as the so urce responsible for the activity observed in the BD+40 region.