CII em-line stars in LMC. II. Final results

The goal is to identify and study [WC11] stars, the coolest of the low-mass Wolf-Rayet sequence, and a subset of central stars of planetary nebulae where the CII lines are known to be especially prominent. A recent serendipitous discovery of an LMC [WC11] raised the possibility that these objects, although difficult to identify, might in fact be more common than previously believed.

Several new members of this rare class have been found in this survey. It now seems clear, however, that a significant number of these stars are not hiding among the general [WC] population. We point out that the CII doublet intensity ratio observed in our spectra proves to neatly divide the objects into two distinct groups, with the CII emission likely originating from either the stellar wind or a surrounding nebula.