Interstellar extinction variations in the Large Magellanic Cloud.

Abstract

The properties of ultraviolet interstellar extinction in the Large Magellanic Cloud (LMC) are investigated, with particular emphasis on the issue of regional variability. New IUE observations of reddened and standard stars are combined with existing data from the IUE archives. The author finds essentially identical extinction properties toward 12 stars located within about 500 pc projected distance of the core of the 30 Dor nebula. The extinction curve toward these stars possesses a weak 2175 Å extinction bump and a steep far-ultraviolet rise. Six reddened stars located outside the 30 Dor region yield extinction curves which are significantly weaker in the far-ultraviolet than the 30 Dor curve. These six curves all have similar far-ultraviolet strengths but show a range of 2175 Å bump strengths. The results suggest that "typical" LMC extinction curves may not differ from typical Milky Way curves as much as has been inferred from past studies which were dominated by stars near 30 Dor.