DD 13: A Very Young and Heavily Reddened Early O Star in the Large Magellanic Cloud

In this paper we investigate the Large Magellanic Cloud star DD 13, which is likely the major ionizing source of the nebula N 159A. We have obtained new optical spectroscopy and new estimates of the broad- band photometric properties of DD 13. We find a spectral type of 03-06 V, E(B- V) = 0.64, and My = - 6.93. The spectral type cannot be more precisely defined due to contamination of the spectral data by nebular emission, obliterating the important He I classification lines. These results, plus a published estimate of the Lyman continuum photon injection rate into N 159A, suggest that DD 13 actually consists of ~2-4 young, early O stars still enshrouded by their natal dust cloud. The star DD 13 may be a younger example of the type of tight cluster represented by the LMC "star" Sk-66^deg^41, recently revealed to be composed of six or more components.