View from the north ecliptic pole showing the location of Helios-1 (red symbol) and IMP-8 (black symbol) on day 149 of 1980 (1980 May 28). Nominal interplanetary magnetic field lines are shown connecting each spacecraft with the Sun (yellow circle at the center, not to scale) considering the solar wind speed measured during the SEP events. The purple line indicates the longitude of the parent active region at the time of the second event (W35 as seen from Earth).