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The Ulysses neutral gas experiment: Determination of the velocity and temperature of the interstellar neutral helium
Rosenbauer, H.; Witte, M.; Banaszkiewicz, M. +1 more
A new technique to directly detect low energy neutral helium has been developed and successfully used in space for the first time. It makes possible the in-situ measurement of the local angular distribution of the flow of interstellar neutral helium in the inner heliosphere. Based on the transformation of a velocity distribution, using Liouville's…
Magnetic fields throughout the heliosphere
Smith, Edward J.
Measurements of the heliospheric magnetic field made over the last several years are surveyed with emphasis on Pioneer 11 observations near 35 AU and Ulysses observations between 1 and 5 AU. The increase in field magnitude at 1 AU near the recent sunspot maximum is also seen at Pioneer 11. Extrapolation of the magnitude and azimuthal component of …
Propagation of jovian electrons in and out of the ecliptic
Sierks, H.; Kunow, H.; Wibberenz, G. +5 more
Since its switch-on in Oct. 90, the Kiel Electron Telescope onboard Ulysses has detected many quiet time increases of the flux of 3-30 MeV electrons, known to originate from Jupiter. We report on the long term variations of this flux for the Ulysses ecliptic journey, and at the beginning of the out of ecliptic phase. They are well accounted for by…
Solar wind composition measurements by the Ulysses SWICS experiment during transient solar wind flows
Geiss, J.; Galvin, A. B.; Ipavich, F. M. +3 more
For the March/April 1991 time period, the alpha/proton abundance ratio, the proton kinetic temperature and speed distributions, and the relative abundance of O+7 to O+6 is determined over each 13-minute duty cycle of the Solar Wind Ion Composition Spectrometer (SWICS) experiment on Ulysses. The ratio (as a relative measure of ionization temperatur…
Measurements of the interstellar gas
Lallement, R.
Two types of interstellar gas observations are considered; namely those made in the local interstellar medium on paths to nearby stars, and those obtained from the study of solar system gas. Optical measurements, and in particular Hubble Space Telescope spectra of the star Capella, have recently confirmed detection of the Local Interstellar Cloud …
Solar wind thermal electrons from 1.15 to 5.34 AU: Ulysses observations
Balogh, A.; McComas, D. J.; Goldstein, B. E. +3 more
Using unique 3-d velocity space measurements by the Ulysses solar wind plasma experiment from 1.15 to 5.34 AU, we assess the radial gradient in thermal electron temperature. Until 3.8 AU, the gradient was steeper than previously reported but flatter than adiabatic; after 3.8 AU the gradient flattened. Trends in the observed electron distribution s…
Cospin let observations of recurrent energetic particle events during the in-ecliptic phase of the Ulysses mission
Bame, S. J.; Sanderson, T. R.; Marsden, R. G. +1 more
The Ulysses spacecraft, launched in October 1990, traversed the in-ecliptic region of the heliosphere from 1 to 5 AU during the post-maximum phase of solar cycle 22 prior to its encounter with Jupiter in February 1992. In the period from launch up to mid-1991, particle events were dominated by the effects of large-scale transient structures in the…
Solar energetic particles in the intermediate region of the heliosphere
Kunow, H.; Wibberenz, G.; Heber, B. +2 more
Energetic particle increases in the energy range 4 to 130 MeV observed by the Kiel Electron Telescope (KET) during the in-ecliptic part of the ULYSSES mission between 1 and 5.4 AU differ distinctly from their appearance in the inner heliosphere inside 1 AU. Prompt events are rare, and for most of the events velocity dispersion is lacking. The obse…
The interplanetary magnetic field from 1 to 5 AU: Ulysses observations
Balogh, A.; Tsurutani, B. T.; Forsyth, R. J. +3 more
Observations of the Interplanetary Magnetic Field (IMF), carried out from October 1990 to February 1992, during the in-ecliptic phase of the Ulysses mission, are presented in this paper. The observations were made between 1 and 5.4 AU, during a different phase of the solar cycle from previous missions. The large scale reorganisation of the solar c…
Sulfur abundances in the solar wind measured by SWICS on Ulysses
Geiss, J.; Galvin, A. B.; Ipavich, F. M. +4 more
One of the nine experiments on Ulysses (launched October, 1990), the Solar Wind Ion Composition Spectrometer, utilizes an energy per charge deflection system along with time of flight technology to uniquely determine the mass and mass per charge of solar wind particles. Thus the composition of various solar wind types can be analyzed. Using the SW…