Interstellar extinction in the Large Magellanic Cloud.

Abstract

Interstellar extinction in the ultraviolet as a function of position in the Large Magellanic Cloud (LMC) is investigated using an enlarged sample of reddened and comparison stars. With the exception of SK-68-108, the extinction curves of the LMC stars do not show significant variation. The mean extinction curve increases towards 2200 A, with some maxima near 2200 A and 1900 A. Differences in the mean galactic law include the weak 2200 A feature and a significantly higher LMC extinction in the ultraviolet. The strength of the 1920 A feature is determined as a function of luminosity and spectral type, and extinction curves are corrected for the mismatch of this feature. Intrinsic colors of luminous cloud members are also derived. The possibility of local variations associated with circumstellar clouds is not ruled out due to the heavily reddened star SK-69-108, and it is suggested that the LMC extinction curves are due to stellar Fe III lines being stronger in some reddened stars than in the comparison stars.