Search Publications
More about the structure of the high latitude Jovian aurorae
Prangé, Renée; Pallier, Laurent
This study is based on the determination of a 'reference' main oval for Jupiter's aurora from a series of high-resolution images taken with the Faint Object Camera on board the Hubble Space Telescope in the H 2 Lyman bands centered near 1550 Å. We have taken advantage of the visibility of the northern auroral oval over a large range of …
Modelling of thunderclouds and lightning generation on Titan
Lammer, H.; Molina-Cuberos, G. J.; Tokano, T. +1 more
The likelihood of lightning generation in Titan's troposphere is investigated by theoretical consideration and a numerical one-dimensional time-dependent thundercloud model. The main cloud electrification hypotheses proposed for terrestrial thunderstorms are examined taking into account recent knowledge concerning Titan's atmospheric state, especi…
Low-frequency limit of Jovian radio emissions and implications on source locations and Io plasma wake
Zarka, Philippe; Crary, Frank J.; Queinnec, Julien
After deriving from Ulysses-URAP measurements the low-frequency limit of the Jovian hectometer emission spectrum ( 250±50 kHz at the -20 dB level below the emission peak), and confirming the absence of Io's control on Jovian radio emission below ∼1 MHz, we propose a single common explanation for these low-frequency limits: both are well explained …
Four years of Ulysses dust data: 1996-1999
Krüger, H.; Srama, R.; Hamilton, D. P. +17 more
The Ulysses spacecraft is orbiting the Sun on a highly inclined ellipse ( i=79°, perihelion distance 1.3 AU, aphelion distance 5.4 AU). Between January 1996 and December 1999 the spacecraft was beyond 3 AU from the Sun and crossed the ecliptic plane at aphelion in May 1998. In this 4-yr period 218 dust impacts were recorded with the dust detector …
Local time asymmetry of the equatorial current sheet in Jupiter's magnetosphere
Cowley, S. W. H.; Bunce, E. J.
We provide a first systematic comparison of the radial fields associated with the equatorial current sheet in the Jovian magnetosphere which were observed during the flybys of the Pioneer-10 and -11, Voyager-1 and -2, and Ulysses spacecraft. These data span a ∼210° range of azimuths about the planet, from dusk via noon to the post-midnight sector.…
Periodic signals in Ulysses' energetic particle events upstream and downstream from the Jovian bow shock
Sarris, E. T.; Anagnostopoulos, G. C.; Marhavilas, P. K.
We present results from a statistical analysis of energetic particle events, observed by the Heliosphere instrument for spectra, composition, and anisotrophy at low energies (HI-SCALE) instrument onboard Ulysses, upstream from the bow shock of Jupiter, during the inbound and outbound trajectory of the spacecraft. A harmonic analysis on the intensi…
Large-scale energetic particle layers in the high latitude Jovian magnetosphere
Anagnostopoulos, G. C.; Karanikola, I.; Marhavilas, P.
This study presents an analysis of long lasting (∼2- 3 h) energetic (≳60 keV) ion and (≳40 keV) electron events observed by the HISCALE instrumentation on board Ulysses in the high latitude Jovian magnetosphere. The high latitude events in the prenoon dayside (d 36-38, 1992) and the south duskside (d 40-43, 1992) magnetosphere are different from t…
Rotational periods of asteroids II
Riccioli, D.; Blanco, C.; Cigna, M.
In the framework of the photoelectric asteroid observational program undertaken at Catania University to collect lightcurves apt to apply the pole computational methods, the V-band lightcurves and the values of the synodic rotational period and of the average B- V colour index of 5 Astrea, 6 Hebe, 12 Victoria, 13 Egeria, 26 Proserpina, 34 Circe, 6…
Asteroids in the infrared - Serendipitous observations with ISO
Müller, T. G.
The infrared space observatory (ISO) observed many asteroids in great detail, including near-Earth asteroids (NEA). Additionally, a large number of observing programmes contain serendipitous observations of known and unknown solar system objects (SSO). The ISO specific constraints, like sensitivity, visibility and orbit parallax and their conseque…
The Jovian HOM and bKOM radio emissions observed by Wind//WAVES and by Ulysses//URAP
MacDowall, R. J.; Kaiser, M. L.; Lecacheux, A. +1 more
During 1995 and into 1996, both the Jovian hectometric radio emission (HOM) and the Jovian broadband radio emission (bKOM) were received occasionally by the Radio and Plasma Wave Investigation (WAVES) on board the Wind spacecraft and by the Unified Radio and Plasma Experiment (URAP) on board the Ulysses spacecraft. Ulysses was then at distances of…