We know that our sun is a busy, active star that occasionally flashes brighter than usual in electromagnetic eruptions called solar flares. Scientists also know that such flares tend to happen near to sunspots and that they seem to be associated with the movement of plasma. But there’s still much we don’t understand about the formation of flares, and in particular how to predict them, which is important for predicting space weather.
To learn more about flares, researchers at the New Jersey Institute of Technology (NJIT) have trained the Expanded Owens Valley Solar Array (EOVSA) radio telescope on the sun to capture flare activity since 2017. Now, they have released data on the first-ever flare captured moment by moment, pinpointing the exact time and place the flare burst out of the sun’s surface with the energy equivalent to 1 billion degrees Fahrenheit.
“We have been able to pinpoint the most critical location of the magnetic energy release in the corona,” Gregory Fleishman, professor of physics in NJIT’s Center for Solar-Terrestrial Research, said in a statement. “These are the first images that capture the microphysics of a flare — the detailed chain of processes that occur on small spatial and time scales that enable the energy conversion.”
Image of a solar flare. New Jersey Institute of Technology
The research has revealed that flares share processes with other astronomical phenomena like gamma-ray bursts, and are similar to processes seen in research into the generation of fusion energy. As the EOVSA instrument is able to capture images in the optical, ultraviolet, X-ray, and radio wavelengths, it was able to see the way magnetic field lines on the sun gives rise to flares.
“Microwave emission is the only mechanism that is sensitive to the coronal magnetic field environment, so the unique, high-cadence EOVSA microwave spectral observations are the key to enabling this discovery of rapid changes in the magnetic field,” Dale Gary, professor of physics at NJIT and director of EOVSA, said in the statement. “The measurement is possible because the high-energy electrons traveling in the coronal magnetic field dominantly emit their magnetic-sensitive radiation in the microwave range.”
This data helps scientists understand how erupting flares cause shock waves which can damage spacecraft and pose a threat to astronauts. In the future, the EOVSA tool will continue to capture images of the sun for researchers to investigate and will be used to create daily maps of the magnetic fields around the sun.
The findings are published in the journal Science.