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Register a new userThe LMC transition star R84 and the core of the LH 39 OB association
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M. Heydari-Malayeri
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On the basis of sub-arcsecond optical imaging we resolve and study the core components of the LMC OB association LH 39. The central star of the association, the rare transition object R84, is also investigated using CASPEC echelle spectroscopy. A new, powerful image restoration code that conserves the fluxes allows us to obtain the magnitudes and colors of the components. We bring out some 30 stars in a ~16x16, area centered on R84. At a resolution of 0.19, the closest components to R84 are shown to lie at 1.1 NW and 1.7 NW respectively of the transition star. One of these stars is the reddest star of the field after R84 but turns out to be too faint to correspond to the red M2 supergiant previously reported to contaminate the spectrum of R84. If the late-type spectrum is due to a line-of-sight supergiant with a luminosity comparable to R84, it should lie closer than 0.12 to R84. The transition star shows spectral variability between 1982 and 1991. We also note some slight radial velocity variations of the Of emission lines over timescales of several years. Furthermore, we discuss the apparent absence of O type stars in this association.
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