Search Publications
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…
The highly ionised absorbing material in MR2251-178
Mineo, T.; Stewart, G. C.
Ginga observations have suggested the presence of iron absorption edges at energies appropriate for highly ionised material in the X-ray spectra of a significant number of active galactic nuclei. Here, we present a detailed self-consistent analysis of a series of Ginga and EXOSAT observations of MR2251-178, the original prototype of this warm-abso…
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…
Solar wind composition and expectations for high solar latitudes
Geiss, J.; von Steiger, R.
Instruments on board the Ulysses spacecraft are to investigate, for the first time, the solar wind in the three principal domains of solar latitude. (1) During Ulysses' flight in the ecliptic plane the solar wind near the current sheet was continuously measured, and its composition was determined with unprecedented sensitivity and mass resolution …
The low-frequency interplanetary radiation
Kurth, W. S.
Observations of the low-frequency interplanetary radiation have continued, although no major activity has begun since mid-1991. Theoretical work has been completed which suggests that the long-speculated source at the termination shock is feasible and could at least qualitatively account for several aspects of the observations, although some diffi…
Initial results from the solar flare X-ray observations with ulysses
Hurley, K.; Sommer, M.; Kane, S. R. +1 more
The Solar X-Ray/Cosmic Gamma-Ray Burst Experiment aboard the Ulysses spacecraft measures hard X-ray spectra in the nominal energy range 15-150 keV, which can be changed by ground command. Since the experiment turn-on on 11 November 1990, it has recorded hard X-ray emission from ~100 solar flares of GOES soft X-ray class > M and several hundred …