Post-eclipse Temporal Variability of Neutral Sodium Near Io
Abstract
In 1998, 1999, 2000, and 2002 we conducted spectroscopic observations of neutral Sodium D-line emissions in the vicinity of Io, using the NSO McMath-Pierce main telescope. This facility is equipped with an echelle spectrograph and a Bowen image slicer that covers a 10" x 10" field of view. The light from each of ten image slices can be subdivided into ~30 separate spectra, yielding a 10 x 30 array of spectra, which are analyzed and reassembled into an image. In addition to the spatial and temporal intensity information, the instrument's high spectral resolving power (~140,000) and simultaneous capture of both Na D-lines provide insight into the velocity structure and optical thickness of the gas. We obtained four sequences of five-minute integrations after Io's egress from eclipse. The data reveals a period of steady increase in intensity beginning immediately after Io emerges from Jupiter's shadow. We will discuss these results and their implications for the post-eclipse evolution of Io's sodium atmosphere.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2002
- Bibcode:
- 2002AGUSM.P21B..05C
- Keywords:
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- 6218 Jovian satellites