High Resolution Spectroscopy of Io [O I] 6300 Angstroms Emission

As part of our long-term Io monitoring campaign, high resolution (R ~ 120000) observations of the neutral oxygen emission (6300 Angstroms), averaged over Io's disk, were obtained at the NSO McMath-Pierce main telescope. The stellar spectrograph, equipped with an image slicer (10 slices = 5'' x 5'' field of view), was used for observations taken from mid-June to mid-October, 1997. Spectra with good signal-to-noise were obtained for most Io orbital and Io plasma torus longitudes. These data are examined for orbital and plasma torus phase relationships. In addition, the data are examined for long term variability and compared to earlier data taken by Scherb and Smyth. The data are also complementary to and near simultaneous with STIS ultraviolet observations of neutral oxygen and sulfur emissions associated with Io taken by Moos(JHU) and Roesler (U Wisconsin) (abstracts in this meeting).