Emission of cosmic rays from Jupiter: magnetospheres as possible sources of cosmic rays

Measurements made recently with the PAMELA satellite during a period of 8 years have shown with good evidence that a fraction of the cosmic rays detected on Earth comes from Jupiter. This result draws attention to the idea that magnetospheres of astrophysical objects could contribute to the sources of cosmic rays. In this paper we extend our analysis of the cosmic rays measurements made with PAMELA finding further evidence that the cosmic ray fluxes are larger on average when the Earth orbit intersects the lines of the measured interplanetary magnetic field connecting Jupiter with Earth. This effect shows up with more than ten standard deviations, difficult to explain without the idea that part of the cosmic ray protons comes directly from the Jupiter magnetosphere.