Knowledge Bank

Since the initial observations of the $2\mu m2\nu 2(2)\to 01.2$ and $4\mu m\nu 2\to 03$ 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 $\nu 2\to 0$ fundamental band of $H3+$ 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 $2\nu 2(0)\to \nu 2(J=9,K=9\to J=8,G=9,U=1)$ 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 $H3+$ emission. The intensity of the transition at $3.53\mu m(J=4,G=3,U=-1\to J=3,K=3)$ in Saturn was weaker than in Jupiter by about a factor of 130, and the total column density was $1.0\times 1011cm-2$. All observations were made with the CGS4 spectrometer at the United Kingdom Infrared Telescope on Mauna Kea. Hawaii.