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T.R. Gull (NASA/GSFC/LASP), K. Davidson, K. Ishibashi (U. Minnesota)
We now have Space Telescope Imaging Spectrograph (STIS) spectra at four epochs (Dec 1997; Mar 1998; Nov 1998 and Feb 1999). The Mar 1998 and Feb 1999 spectra are complete from 1640A to 10400A at a resolving power of 5000 (or better) and angular resolution of 0.1". Both spectral and spatial variations abound as Eta Carina emerges from its minimum excitation (Dec 1997-Mar 1998) towards its maximum (~Oct 2000). The stellar line profiles are changing, especially the Balmer lines. The Homunculus, a reflection nebula, shows a short term history especially of the Hydrogen alpha line profile with different views of the stellar disk(s?). A deep absorption line is noted in many Balmer lines, arising from the metastable 2S state, and is seen for the first time in extended nebulae. Within the Homunculus is a smaller, emission-line nebula, which we call the Integral Nebula. This two arcsecond radius structure is seen in multiple [Fe II] lines, in addition to the hydrogen, helium and [N II] lines. We will describe changes in structure and excitation during the recent past.
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