HUBBLE-SPACE-TELESCOPE GODDARD HIGH-RESOLUTION SPECTROGRAPH H2 ROTATIONAL SPECTRA OF JUPITER AURORA

We have observed the emission spectrum from Jupiter's north auroral at mosphere with 0.57 angstrom spectral resolution over 1204-1241 angstro m. Bright emissions have been detected from 50-degrees to 60-degrees l atitude at locations consistent with 6 to 30 R(J) auroral ovals, with much fainter emissions away from the auroral ovals. The emission spect rum is well fitted by both laboratory spectra and theoretical models o f optically thin electron excited H-2, with added Doppler-broadened Ly alpha emission. The observed Lyalpha emission wings extend more than 1 angstrom from line center and appear correlated in strength with the H-2 brightness. Individual rotational lines in the H-2 Werner band sys tem are resolved, allowing a determination of the H-2 rotational tempe rature at the altitude of the emission. We derive best-fit temperature s from 400-450 to 700-750 K, with the auroral emission layer temperatu re changing either across the auroral oval or over several days' time. These observations demonstrate for the first time the ability to meas ure the observed rapid H-2 temperature variations across Jupiter's aur oral atmosphere.