Solar orbiter captures close-ups of energetic particles ejected from the sun

Scientists at the Southwest Research Institute (SwRI) have recently obtained unprecedented close-up images of energetic particles emitted from the sun. These high-resolution images were captured by the European Space Agency’s Solar Orbiter, a satellite designed to observe the sun, which was launched in 2020. By positioning itself just half an astronomical unit (AU) away from the sun (approximately 46.5 million miles), the Solar Orbiter provided scientists with detailed views of solar events.

The researchers discovered six recurring bursts of energetic ions in 2022, which were associated with magnetic reconnection involving magnetic field lines open to interplanetary space. Such activity has been frequently detected by the Solar Orbiter, but this particular period exhibited unusual elemental compositions. In one instance, the intensity of the rare isotope Helium-3 exceeded that of hydrogen, the most abundant element on the sun. Additionally, the levels of iron were similar to Helium-4, the sun’s second most abundant element. However, in a subsequent burst just two days later, the amount of Helium-3 had dramatically decreased to almost negligible levels.

Dr. Radoslav Bucik, the lead author of the study published in Astronomy & Astrophysics Letters, explained that the varying elemental and spectral characteristics observed in these recurrent bursts are linked to the shape and size of the jets from which the particles originate, as well as the distribution of the underlying photospheric field, which evolves over time. Understanding these variations in events originating from a single source can provide insights into the mechanism behind solar flares’ acceleration.

The Solar Orbiter’s observations are particularly valuable due to the minimal propagation effects on abundance measurements near the sun. Being positioned at a distance of only 0.5 AU enables the scientific team to obtain remarkably detailed views of solar events. Dr. Bucik emphasized that the increased spatial resolution at this closer distance offers a deeper understanding of the source of energetic particles, including the internal structure associated with acceleration processes during the evolution of injections. Comparatively, observations from twice that distance, 1 AU, are less clear.

In the future, the SwRI team hopes to gather even more knowledge from the Solar Orbiter’s closest approaches to the sun, which will take place at a distance of 0.3 AU. These observations have the potential to improve predictions of solar energetic particle events, which can pose risks to satellites, equipment, and astronauts. By comprehending the acceleration mechanisms and conditions under which these particles propagate away from the sun, scientists aim to enhance our ability to protect technology and individuals from their potentially harmful effects.

Source: Southwest Research Institute

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