Search Publications
Measurements of H I and O VI velocity distributions in the extended solar corona with UVCS/SOHO and UVCS/Spartan 201
Romoli, M.; Raymond, J. C.; Naletto, G. +23 more
The Ultraviolet Coronagraph Spectrometer on the Solar and Heliospheric Observatory, UVCS/SOHO, and the Ultraviolet Coronal Spectrometer on the Spartan 201 satellite, UVCS/Spartan, have been used to measure H I 1215.67 A˚ line profiles in polar coronal holes of the Sun at projected heliocentric heights between 1.5 and 3.0 R_solar. UVCS/SOHO also me…
MeV to GeV electron propagation and modulation: results of the KET-telescope onboard ULYSSES
Ferrando, P.
The KET instrument onboard Ulysses is continuously monitoring the flux of MeV to GeV electrons. I summarize here the main results obtained with data from the ~ 7 MeV and > 300 MeV electron KET channels, collected from launch up to the end of 1995 after completion of the Ulysses prime mission. Regarding low energy electrons, the stress is put on…
The heliospheric modulation of galactic cosmic rays at solar minimum
Potgieter, M. S.
The observations acquired by the Ulysses spacecraft since launch, but especially during the recent fast latitude scan, have provided a comprehensive, 3-dimensional view of the inner heliosphere. Together with the observations by IMP 8, Pioneer 10 and the two Voyagers, a wealth of new observations on particles and fields enables us to improve signi…
Radial and azimuthal components of the heliospheric magnetic field: ulysses observations
Forsyth, R.; Balogh, A.; Burton, M. E. +2 more
Two invariants associated with the Parker model of the solar wind involve the radial, B_R, and azimuthal, B_T, components of the heliospheric magnetic field. These invariants have been investigated using Ulysses data obtained at high latitudes in both the north and south solar hemispheres. The magnetic flux invariant, r^2B_R, is essentially indepe…
The dust sensor for CASSINI
Grün, Eberhard; Srama, Ralf
In October 1997 a unique mission to the Saturnian system will be launched by NASA, the CASSINI mission. One goal of this mission is to study the Saturnian dust environment, and for this task, the COSMIC DUST ANALYZER (CDA) has been developed and is currently under test. Impact ionization is used to determine the speed (1 - 100 km/s) and the mass (…
Merging 4 spacecraft data: concepts used for analysing discontinuities
Glassmeier, K. -H.; Dunlop, M. W.; Southwood, D. J. +2 more
Shocks and discontinuities in space plasmas have received much attention in both theoretical studies and spacecraft data analyses. The advent of multi-spacecraft missions, such as ISEE, have provided for a vast improvement of experimental information available on these structures. The ESA CLUSTER, multi-spacecraft mission presents the community wi…
Solar modulation of galactic cosmic rays: the 3D heliosphere
Heber, Bernd; Potgieter, Marius S.; Ferrando, Philippe
The cosmic ray flux observed with the Kiel Electron Telescope onboard the Ulysses space probe varies with solar activity as well as with heliospheric position. The Ulysses' fast latitude scan performed in less than one year between September 1994 to August 1995 allowed us to obtain unique data about the latitudinal dependence of cosmic ray fluxes …
Compressive character of low frequency waves driven by newborn ions at comet Grigg-Skjellerup
Coates, A. J.; Belmont, G.; Neubauer, F. M. +2 more
The investigation by Giotto of the environment of comet P/Grigg-Skjellerup has provided a large set of observations on cometary low-frequency waves for a weakly active comet, after the observations at comets P/Giacobini-Zinner and P/Halley. A large amount of waves are observed at frequencies close to the local water group ion cyclotron frequencies…
Cosmic ray latitudinal effects predicted by a three-dimensional drift model
Potgieter, M. S.; Burger, R. A.; Hattingh, M. +1 more
The Ulysses spacecraft measured surprisingly small latitudinal gradients during its first passage through the polar regions of the heliosphere. This is in contrast to predictions made with two-dimensional drift models for A > 0 magnetic polarity epochs during solar minimum modulation conditions. Several modifications to drift models have been i…
Properties of hydromagnetic waves in the polar caps: ulysses
Forsyth, R.; Balogh, A.; Tsurutani, B. T. +3 more
Properties of the large amplitude Alfvén waves which are a dominant feature of the high latitude solar wind have been studied during the pole-to-pole passage of Ulysses. In addition, an effort has begun to identify magnetosonic waves at high latitude in spite of their expected small amplitude and the presence of the large amplitude Alfvén waves. T…