Luminous composite stars in the Large Magellanic cloud

Line identifications, velocities, and line strengths are presented for four luminous composite systems in the LMC: R67, R84, R94, and R108. Estimates of the luminosities of the cool companions suggest they are similar to other supergiants in both the LMC and the Galaxy. From measurements of the ratio of blue to red stars with wavelength it is inferred that the blue components are several magnitudes brighter (and possibly more massive) than their nearest counterparts (the VV Cephei stars) in the Galaxy. Other spectroscopic evidence shows that three of these systems also have a higher excitation, more extensive emission regions, or both, than the VV Cep stars.