Time Dependent Composition in the December 2006 SEP Events
Multipoint observations of He-rich solar energetic particle (SEP) events using instruments on the ACE and STEREO have been made over the period January 2007 to May 2009, during which the separation between the two STEREO spacecraft in heliolongitude increased from 0.5 to 95 . Relatively quiet conditions on the Sun allowed identification of probable source regions. In one event (4 November 2008), ions were detected at STEREOB and ACE and electrons at all three spacecraft. The longitudinal distributions of energetic particles from He-rich SEP events are discussed and compared with results from previous studies.