Energetic Particle Observations Made by the High Energy Telescopes During the STEREO Mission

The High Energy Telecopes (HETs) on the STEREO A and B spacecraft make observations of 0.7-4 MeV electrons and 13.6-100 MeV protons. We summarize some of the results from the HETs since launch in October, 2006. In particular, nearly 340 individual particle events that include 25 MeV protons have been detected at either the STEREOs and/or near Earth spacecraft, of which around 40 were observed at all three locations before the loss of contact with STEREO B in October, 2014. Modest 25 MeV proton events continue to be observed during the late decay phase of solar cycle 24. We summarize some of the properties of these events, illustrate recent examples, and discuss lessons learned for future missions.