SIMBAD references

We have remeasured the H_2 column densities along lines of sight to the Large Magellanic Cloud (LMC) using spectra taken by the Hopkins Ultraviolet Telescope (HUT). Three lines of sight were analyzed using the pair method and previously determined Fitzpatrick & Massa (1986) extinction parameters to allow H_2 absorption models to be fitted. Substantial improvements over the values first reported by Clayton et al. (1996) were made for two of the three lines of sight. Comparisons between LMC and Galactic environments suggest that the factors which lead to extinction curve variations (e.g. metallicity or shocks) do not affect the efficiency of H_2 formation on the surfaces of the dust grains: N_{H2}/E(B-V) values are approximately the same in both galaxies despite large differences in N_{HI}/E(\B-V).(c) Astronomical Society of the Pacific