The SEP Instrument Suite on STEREO

SIT HET and LET, on SEP-Central SEPT-E and SEPT-NS

Note About Data Gaps



July, 2015: Change in SEP Instrument Suite Viewing Directions: After solar conjunction, the two STEREO spacecraft have been rolled 180 degrees about the spacecraft-Sun line in order to allow the high gain antenna to remain pointing at Earth. Consequently, the nominal pointing directions of the SEP suite of instruments are now different. This will remain the case until the spacecraft pass by Earth again in 2023.

The Solar Terrestrial Relations Observatory (STEREO) will employ two nearly identical observatories in orbit about the Sun (one moving ahead of the Earth, and one moving behind) to provide the first-ever 3-D images of coronal mass ejections (CMEs). These stereo images will be supplemented by multi-point in situ measurements of solar wind and CME plasma and the energetic particles accelerated in association with solar eruptions, and by multipoint observations of radio bursts occurring in these events.

The Solar Energetic Particle (SEP) instrument suite provides four solar energetic particle instruments for the IMPACT (In-Situ Measurements of Particles and CME Transients) investigation on STEREO. IMPACT provides measurements of solar wind and suprathermal electrons, interplanetary magnetic fields, and solar energetic particles. The SEP suite is composed of the following elements:

Other related STEREO web sites: