Search Publications

Weakening of Jupiter's main auroral emission during January 2014

Fujimoto, M.; Yoshioka, K.; Steffl, A. J. +13 more

In January 2014 Jupiter's FUV main auroral oval decreased its emitted power by 70% and shifted equatorward by ∼1°. Intense, low-latitude features were also detected. The decrease in emitted power is attributed to a decrease in auroral current density rather than electron energy. This could be caused by a decrease in the source electron density, an…

Ceres: Sulfur deposits and graphitized carbon

Vilas, Faith; Li, Jian-Yang; Hendrix, Amanda R.

We report new results from observations of the dwarf planet Ceres using the Hubble Space Telescope in the spectral range 1160-5700 Å. Comparisons between Ceres' UV-visible spectra and laboratory measurements indicate that both sulfur species and graphitized carbon are important on Ceres' surface. We find a latitudinal gradient in UV absorption, wi…

Constraints on an exosphere at Ceres from Hubble Space Telescope observations

Saur, Joachim; Roth, Lorenz; Feldman, Paul D. +5 more

We report far ultraviolet observations of Ceres obtained with the Cosmic Origin Spectrograph (COS) of the Hubble Space Telescope in the search for atomic emissions from an exosphere. The derived brightnesses at the oxygen lines at 1304 Å and 1356 Å are consistent with zero signals within the 1σ propagated statistical uncertainties. The OI 1304 Å b…

Dynamics of the flares in the active polar region of Jupiter

Badman, S. V.; Bonfond, B.; Gérard, J. -C. +2 more

The duskside of the polar region of Jupiter's UV aurorae, called the active region, sometimes exhibits quasiperiodic (QP) flares on timescales of 2-3 min. Based on Hubble Space Telescope Far-UV time-tag images, we show for the first time that the Northern Hemisphere also displays QP flares. The area covered by these flares can reach up to 2.4 × 10…