The SEP Instrument Suite on STEREO
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| SIT | HET and LET, on SEP-Central | SEPT-E and SEPT-NS |
Note About Data Gaps
STEREO-A
- August 19, 2014: Telemetry is reduced in preparation for Solar Conjunction. SEP instrument suite data coverage is only a few hours per day.
- Jan 6, 2015: Telemetry is further reduced in preparation for Solar Conjunction. SEP instrument suite data coverage is only a few hours per day, and only one minute of data every 5 minutes is recorded.
- March 21, 2015: Solar Conjunction period begins. SEP instrument suite turned off. No data.
- July 15, 2015: Solar Conjunction period ends. SEP instrument suite data returns, coverage is only a few hours per day.
- November 16, 2015: Full SEP instrument suite data coverage returns.
- NOTE: Beacon data from the SEP instrument suite is available for the periods of reduced telemetry just preceding and after the solar conjunction.
- More information about STEREO Solar Conjunction
STEREO-B
- September 27, 2014: Shut down for Solar Conjunction Test.
- October 1, 2014: Communication with STEREO-B spacecraft lost. Recovery attempts have ceased, see STEREO Science Center STEREO-B Status
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:
- High Energy Telescope (HET)
- Low Energy Telescope (LET)
- Solar Electron Proton Telescope (SEPT)
- Suprathermal Ion Telescope (SIT)
- SEP-Central - the central command/control and data acquisition unit for the suite
Other related STEREO web sites: