OUTER LAYERS OF A CARBON STAR - THE VIEW FROM THE HUBBLE-SPACE-TELESCOPE

To advance our understanding of the relationship between stellar chrom ospheres and mass loss, which is a common property of carbon stars and other asymptotic giant branch stars, we have obtained ultraviolet spe ctra of the nearby N-type carbon star UU Aur using the Hubble Space Te lescope (HST). In this paper we describe the HST observations, identif y spectral features in both absorption and emission, and attempt to in fer the velocity field in the chromosphere, upper photosphere, and cir cumstellar envelope from spectral line shifts. A mechanism for produci ng fluoresced emission to explain a previously unobserved emission lin e is proposed. Some related ground-based observations are also describ ed.