OBSERVATION OF $H_{3}^{+}$ EMISSION IN PLANETARY ATMOSPHERES: $\nu_{2} \rightarrow 0$ AND $2\nu_{2}(0) \rightarrow \nu_{2}$ IN JUPITER AND $\nu_{2} \rightarrow 0$ IN SATURN
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Date
1993
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Ohio State University
Abstract
Since the initial observations of the $2 \mu m 2 \nu_{2}(2) \rightarrow 01.2$ and $4 \mu m \nu_{2} \rightarrow 0^{3}$ bands of $H3+$ in Jupiter, their temporal variation in the Jovian polar auroral regions has been $established.^{3,4}$ We report five transitions at $3.54 \mu m$ of the $\nu_{2} \rightarrow 0$ fundamental band of $H_{3}^{+}$ observed in emission across Jupiter. The strongest emissions occurred in the polar regions, and their intensities feel off by an order of magnitude away from the poles. Additionally, a hot band transition $2\nu_{2}(0) \rightarrow \nu_{2} (J = 9, K = 9 \rightarrow J = 8, G = 9, U = 1)$ was observed. Three transitions of the $v2 $$ 0$ band at $3.53 \mu m$ and $3.67 \mu m$ were detected in $Saturn.^{5}$ which becomes the third planet to naturally exhibit $H_{3}^{+}$ emission. The intensity of the transition at $3.53 \mu m (J = 4, G = 3, U = -1 \rightarrow J = 3, K = 3)$ in Saturn was weaker than in Jupiter by about a factor of 130, and the total column density was $1.0 \times 10^{11} cm^{-2}$. All observations were made with the CGS4 spectrometer at the United Kingdom Infrared Telescope on Mauna Kea. Hawaii.
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Author Institution: Joint Astronomy Centre; Department of Chemistry and Department of Astronomy and Astrophysics., The University of Chicago
Author Institution: Joint Astronomy Centre; Department of Chemistry and Department of Astronomy and Astrophysics., The University of Chicago