Detection of H3(+) infrared emission lines in Saturn

Abstract

Three emission lines of the nu-2 fundamental vibration-rotation band of H3(+) have been detected in the ionosphere of Saturn near and at its poles. The peak observed column density of H3(+) (at the south limb) is more than two orders of magnitude lower than the column density at the south pole of Jupiter, and is less than that detected from Uranus. While the number and the S/N ratios of observed transitions are not sufficient to determine the temperature and abundance of H3(+) accurately, the observed emission intensities are consistent with a temperature of about 800 K and total column density of about 1.0 x 10 exp 11/sq cm.