The Solar Orbiter spacecraft has traced superfast electrons traveling at nearly the speed of light back to their origins on the Sun, revealing two distinct types of solar outbursts responsible for their acceleration.
Why it matters: Understanding the sources of these Solar Energetic Electrons (SEEs) is crucial for improving space weather predictions and protecting spacecraft and astronauts from potentially damaging high-energy particles.
The details:
- Researchers identified “impulsive” SEE events associated with sudden bursts from solar flares and “gradual” events linked to prolonged waves from coronal mass ejections (CMEs).
- Solar Orbiter’s unique proximity to the Sun allowed for detailed observations of over 300 SEE events between November 2020 and December 2022, the most comprehensive study to date.
- The spacecraft’s instruments measured the electrons in their early, “pristine” state, accurately determining their time and place of origin on the Sun.
- Researchers also studied how electrons behave as they travel through the Solar System, encountering turbulence and scattering that can cause delays in their detection.
The space between the Sun and planets is filled with solar wind, a constant stream of charged particles that drags the Sun’s magnetic field and influences the travel of energetic electrons.
What they’re saying:
- “We see a clear split between ‘impulsive’ particle events, where these energetic electrons speed off the sun’s surface in bursts via solar flares, and ‘gradual’ ones associated with more extended CMEs,” said lead author Alexander Warmuth of the Leibniz Institute for Astrophysics Potsdam (AIP), Germany.
- “Thanks to Solar Orbiter, we’re getting to know our star better than ever,” said Daniel Müller, ESA Project Scientist for Solar Orbiter.
The impact: Distinguishing between the two types of SEE events is vital for accurate space weather forecasting, as CMEs contain more high-energy particles that pose significant threats to spacecraft.
What’s next: ESA’s future mission, Vigil, set to launch in 2031, aims to continuously observe the ‘side’ of the Sun, offering early warnings of potentially hazardous solar events. This research showcases the power of collaboration across European scientists and institutions, and colleagues from the US.
