TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and Hi emission. The molecular ring consists of well-separated cores, which have a volume density of 10(3) cm(-3) and kinematic temperature similar to 20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core "A," which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the " collect and collapse" process functions in this region. The star-forming activities in core "A" seem to be affected by the "radiation-driven implosion" process.