IRAS 18153-1651: an H II region with a possible wind bubble blown by a
  young main-sequence B star
  We report the results of spectroscopic observations and numerical modelling
of the H II region IRAS 18153-1651. Our study was motivated by the discovery of
an optical arc and two main-sequence stars of spectral type B1 and B3 near the
centre of IRAS 18153-1651. We interpret the arc as the edge of the wind bubble
(blown by the B1 star), whose brightness is enhanced by the interaction with a
photoevaporation flow from a nearby molecular cloud. This interpretation
implies that we deal with a unique case of a young massive star (the most
massive member of a recently formed low-mass star cluster) caught just tens of
thousands of years after its stellar wind has begun to blow a bubble into the
surrounding dense medium. Our two-dimensional, radiation-hydrodynamics
simulations of the wind bubble and the H II region around the B1 star provide a
reasonable match to observations, both in terms of morphology and absolute
brightness of the optical and mid-infrared emission, and verify the young age
of IRAS 18153-1651. Taken together our results strongly suggest that we have
revealed the first example of a wind bubble blown by a main-sequence B star.
