The Interstellar Medium toward Supernova 1987A

High-resolution spectra of SN 1987A obtained with the IUE show absorption features from the disk and halo of our Galaxy and the Large Magellanic Cloud. A rich variety of elements and ionization stages is found, including allowed resonance lines of abundant elements with ionization states ranging from C I and O I to Al III, Si IV and C IV. The Si IV and C IV absorption at LMC velocities is ununsually strong toward the supernova as compared to most other stars in the LMC and SMC. The origin of these lines is discussed.