Ulysses cosmic-ray investigations extending from the south to the north polar regions of the Sun and heliosphere.

Abstract

The recent rapid transit of Ulysses from the solar south polar to the north polar region has confirmed the earlier findings by the COsmic-ray and Solar-Particle INvestigations (COSPIN) international consortium and has yielded additional discoveries that are important for understanding heliospheric modulation. High-resolution isotopic measurements of Fe and Ni on Ulysses show that the source composition of these cosmic-ray nuclei is not neutron rich for these elements and is close to solar-system composition.