Aug 27 – 29, 2018
Paris, France
Europe/Paris timezone

The detection of ultra-relativistic electrons in low Earth orbit by the LYRA instrument on board the PROBA2 satellite

Aug 28, 2018, 2:00 PM
Charpak room (Paris, France)

Charpak room

Paris, France

Pierre and Marie Curie campus Sorbonne University
talk Session 2: Results from recent space missions Session 2: Results from recent space missions


Dr Athanassios Katsiyannis (Royal Observatory of Belgium)


We present the analysis of energetic particles, indirectly detected by the Large Yield RAdiometer (LYRA) instrument on board ESA's Project for On-board Autonomy 2 (PROBA2) satellite in the form of microbursts of <10 ms, with a phenomenon duration of 100 s. Combining Energetic Particle Telescope (EPT/PROBA-V) observations with LYRA data for an overlapping period of time, we identified these particles as electrons with an energy range of 2 to 8 MeV. The observed events are strongly correlated to geo-magnetic activity and appear even during modest disturbances. Additionally, they are well confined geographically within the L=4-6 McIlwain zones, and they show prominent dawn-dusk and day-night asymmetries.


Those detections clearly illustrate that although LYRA is built as an EUV irradiometer, it can also reliably detect in-situ relativistic electrons. The scientific value of this discovery and its implication to solar irradiometer designs will also be discussed.

Primary author

Dr Athanassios Katsiyannis (Royal Observatory of Belgium)


Presentation materials