The LMC HII region N 214C and its peculiar nebular blob

We study the Large Magellanic Cloud HII region N 214C using imaging and spectroscopy obtained at the ESO New Technology Telescope. On the basis of the highest resolution images so far obtained of the OB association LH 110, we show that the main exciting source of the HII region, Sk -71 51, is in fact a tight cluster of massive stars consisting of at least 6 components in an area ~ 4" wide. Spectroscopic observations allow us to revise the spectral type of the main component (# 17) to O2 V ((f*)) + OB, a very rare, hot type. We also classify several other stars associated with N 214C and study the extinction and excitation characteristics of the HII region. Moreover, we obtain BVR photometry and astrometry of 2365 stars and from the corresponding color-magnitude diagram study the stellar content of N 214C and the surrounding LH 110. Furthermore, we discover a striking compact blob of ionized gas in the outer northern part of N 214C. A spherical structure of ~ 5" in radius (~ 1.3 pc), it is split into two lobes by absorbing dust running diametrically through its center. We discuss the possible nature of this object.
Low resolution figures. Better quality figures may be obtained from A&A online edition or on request to F. Meynadier