Permanent Sources of Particle Emission from the Sun

Abstract

Protons of energies less than a few MeV are present continuously for periods of several days. During the last solar minimum, these protons might appear in interplanetary space with a recurrence of 27 days over many solar rotations. It is argued that the particles are of solar origin.

For the majority of cases, one may relate particle events with active regions on the sun, even during solar minimum. We thus reject the hypothesis of acceleration of particles in interplanetary space.

Solar corpuscular streams are confined in interplanetary magnetic sectors which can be relatively stable for several rotations. The 27-day recurrence is attributed to two different causes which will be discussed: the first is long-term storage of solar particles; the second is the successive formation of active centers in the same sector and at neighboring longitudes. These two causes will be discussed. Active centers responsible for solar corpuscular events may modify the magnetic sectors in which these particles are confined and by this mechanism the particle pattern itself may be modified. These modifications and some aspects of the magnetic sector origin will be discussed.