Imaging Jupiter's aurorae from H+3 emissions in the 3–4 μm band

Publisher Website
Google Scholar
Abstract
SINCE H+3 was first spectroscopically detected on Jupiter1,2, there has been considerable interest in using this simple molecular ion to probe conditions existing in the planet's auroral regions. Here we present a series of images of Jupiter recorded at wavelengths sensitive to emission by H+3, which reveal the spatial distribution of excited H+3 molecular ions in the jovian ionosphere, as seen from Earth. We believe that they provide high-spatial-resolution images of polar aurorae on Jupiter. They suggest that the intensity of the auroral emission can vary on a timescale of an hour, a shorter period than had previously been noted. We also find that the spatial distribution of H+3 emissions correlates only partially with the loci of auroral activity inferred from ultraviolet and longer-wavelength infrared observations. The H+3 emission may therefore be controlled by auroral processes that are different from those responsible for the ultraviolet and infrared emissions.