The far ultraviolet spectrum of Eta Carinae

The first far ultraviolet high spectral resolution observations of eta Carinae were obtained with the Far Ultraviolet Spectroscopic Explorer satellite in February and March 2000. The observed flux at 1150 Angstrom is similar to 4 x 10(-1)2 erg cm(-2) sec(-1) Angstrom(-1). The flux level declines toward the Lyman limit where converging H-2 and Hi features completely blanket the spectrum, The shape of the spectrum shortward of 1110 A is dominated by strong absorption bands of interstellar H-2. In addition to many strong interstellar atomic species, the spectrum contains several prominent P-Cygni features, including C III 1175, S IV 1063-73, Si III 1113, and NI 1134. The lines are broad with unsaturated absorption troughs, implying that the wind is patchy and/or only partly covers the UV emitting surface. The wind absorption extends to similar to -1000 km s(-1). The large far ultraviolet flux levels at 1150-1180 Angstrom, relative to those observed by HST/STIS, imply that the observed far-UV spectrum is formed in an extended (similar to 1 - 2 arcsec diameter) UV scattering envelope.