Search Publications
Ulysses Above the Sun's South Pole: An Introduction
Smith, Edward J.; Marsden, Richard G.; Page, D. Edgar
Ulysses has explored the field and particle environment of the sun's polar region. The solar wind speed was fast and nearly constant above -50^circ latitude. Compositional differences were observed in slow (low-latitude) solar wind and in fast (high-latitude) solar wind. The radial magnetic field did not change with latitude, implying that polar c…
Hubble Space Telescope Imaging of Neptune's Cloud Structure in 1994
Hammel, H. B.; Lockwood, G. W.; Barnet, C. D. +1 more
Images of Neptune taken at six wavelengths with the Hubble Space Telescope in October and November 1994 revealed several atmospheric features not present at the time of the Voyager spacecraft encounter in 1989. Furthermore, the largest feature seen in 1989, the Great Dark Spot, was gone. A dark spot of comparable size had appeared in the northern …
Observations of Energetic Particles with EPAC on Ulysses in Polar Latitudes of the Heliosphere
Franz, M.; Keppler, E.; Korth, A. +5 more
Measurements with the Energetic Particle Composition instrument (EPAC) aboard Ulysses show particles from near the ecliptic that were apparently accelerated by shocks associated with a corotating interaction region. The particles were detected together with the shocks and even when shocks no longer arrived at Ulysses up to -65^circ of heliographic…
Large-Scale Interplanetary Magnetic Field Configuration Revealed by Solar Radio Bursts
Stone, R. G.; Fainberg, J.; Reiner, M. J.
An instantaneous view of the interplanetary extension of the solar magnetic field is provided here by measurements from a space platform at high ecliptic latitudes of the trajectories of individual type III solar radio bursts. The Ulysses spacecraft provides this unique vantage point with an orbit taking it far from the ecliptic plane. The Ulysses…
Ulysses Radio and Plasma Wave Observations at High Southern Heliographic Latitudes
Goetz, K.; Kellogg, P. J.; MacDowall, R. J. +17 more
Ulysses spacecraft radio and plasma wave observations indicate that some variations in the intensity and occurrence rate of electric and magnetic wave events are functions of heliographic latitude, distance from the sun, and phase of the solar cycle. At high heliographic latitudes, solar type III radio emissions did not descend to the local plasma…
Over the Southern Solar Pole: Low-Energy Interplanetary Charged Particles
Simnett, G. M.; Pick, M.; Anderson, K. A. +11 more
The heliosphere instrument for spectrum, composition, and anisotropy (HISCALE) recorded the fluxes of low-energy ions and electrons (>50 kiloelectron volts) when Ulysses crossed the southern solar polar region and revealed that the large-scale structure of the heliosphere to at least ~-75^circ was significantly influenced by the near-equatorial…
Dark Auroral Oval on Saturn Discovered in Hubble Space Telescope Ultraviolet Images
Ben Jaffel, Lotfi; Sandel, Bill R.; Leers, Veronique
Hubble Space Telescope ultraviolet images of Saturn obtained with the Faint Object Camera near 220 nanometers reveal a dark oval encircling the north magnetic pole of the planet. The opacity has an equivalent width of ~11^circ in latitude and is centered around ~79^circN. The oval shape of the dark structure and its coincidence with the aurora det…
Auroral Signature of Comet Shoemaker-Levy 9 in the Jovian Magnetosphere
Ip, W. H.; Dunlop, M.; Clarke, J. T. +5 more
The electrodynamic interaction of the dust and gas comae of comet Shoemaker-Levy 9 with the jovian magnetosphere was unique and different from the atmospheric effects. Early theoretical predictions of auroral-type processes on the comet magnetic field line and advanced modeling of the time-varying morphology of these lines allowed dedicated observ…
Response of the lo Plasma Torus to Comet Shoemaker-Levy 9
Thomas, N.; Weaver, H. A.; Smith, T. E. +10 more
Spectroscopic and imaging observations of the lo plasma torus were made in June and July 1994 in conjunction with the encounter of periodic comet Shoemaker-Levy 9 with Jupiter. Characteristic emissions from sulfur and oxygen ions showed a decline of about 30 percent in the extreme ultraviolet and an increase of about 40 percent in the far ultravio…