New observations of supernova remnants in the far ultraviolet, especially in the sub-Ly α region, are changing the way we look at the interaction between blast waves and the interstellar medium. I briefly review some of the recent FUV observations of supernova remnants from the Hopkins Ultraviolet Telescope, the Voyager Ultraviolet Spectrometers, as well as IUE and HST.

Introduction

Observations with the IUE satellite over the last 16 years have permitted great strides to be made in better understanding supernova remnants (SNRs) and their interaction with the interstellar medium (ISM). In particular, many filaments have been observed in the galactic SNRs Vela and the Cygnus Loop (Raymond et al. 1988; Raymond, Wallerstein, &, Balick 1991; Hester, Raymond, & Blair 1993; and references therein), and a few studies have been made of bright remnants in the Magellanic Clouds (Vancura et al. 1992a; Blair et al. 1989). However, IUE (and even HST) is limited to wavelengths longer than about 1200 Å, and it is only in the last few years that significant inroads have been made at FUV wavelengths down to the Lyman limit at 912 Å. These observations have been made with the Ultraviolet Spectrometers (UVSs) onboard the Voyager interplanetary spacecraft, and the Hopkins Ultraviolet Telescope (HUT) onboard the Astro-1 space shuttle mission in December 1990. In separate sections below I will discuss some of the recent advances from each of these instruments.