What processes are responsible for our Sun’s solar wind, heat, and energy? This is what a recent study published in Physical Review X hopes to address as a team of researchers presented evidence for a newly discovered type of barrier that the Sun exhibits that could help explain the transfer of energy to heat within the Sun’s outer atmosphere. This study has the potential to help scientists better understand the underlying mechanisms for what drives our Sun and what this could mean for learning about other suns throughout the cosmos.
For the study, the researchers analyzed data obtained from NASA’s Parker Solar Probe, which has been studying the Sun for several years and is also the closest spacecraft to orbit the Sun in history. The goal of the study was to gain insight into how the Sun converts energy into heat, also called turbulent dissipation. The team conducted this by obtaining measurements and data about the Sun’s magnetic field, solar wind, plasma behavior, and the corona, the last of which exists in the Sun’s outer atmosphere.
In the end, the researchers presented evidence for the existence of what they refer to as the “helicity barrier”, which is a long-hypothesized boundary where small-scale energies influence the heating of plasma, which alters the solar wind.
“This paper is important as it provides clear evidence for the presence of the helicity barrier, which answers some long-standing questions about coronal heating and solar wind acceleration, such as the temperature signatures seen in the solar atmosphere, and the variability of different solar wind streams,” said Dr. Christopher Chen, who is a Reader in the Astronomy Unit of the Department of Physics and Astronomy at Queen Mary University of London and a co-author on the study. “This allows us to better understand the fundamental physics of turbulent dissipation, the connection between small-scale physics and the global properties of the heliosphere and make better predictions for space weather.”
Going forward, these findings could help scientists better understand stars in other solar systems, specifically how they convert energy to heat and what this could mean for the formation and evolution of exoplanets, including whether they could host life as we know it. The solar wind influences the Earth’s magnetic field, resulting in the auroras at the north and south polar regions, but if the solar wind is strong enough it could damage satellites and ground stations, which occurred on September 1-2, 1859, in an incident known as the Carrington Event. While the Earth’s magnetic field shields use from the Sun’s harmful radiation and solar wind, exoplanets orbiting other stars with stronger helicity barriers might be influenced differently.
Launched in August 2018, NASA’s Parker Solar Probe has been instrumental in teaching astronomers, specifically solar physics, more about our Sun than ever before. This has been accomplished due to Parker’s ability to travel dangerously close to the Sun using its white reflective shield to protect the scientific instruments designed to gather data about our Sun.
This incredible journey includes setting and breaking several of its records regarding its distance to Sun, with the closest being 6.1 million kilometers (3.8 million miles) from the Sun’s surface, which was accomplished on December 24, 2024. This passage marked the final gravity assist of the spacecraft with mission planners choosing to end the mission as the spacecraft will eventually burn all its fuel. Once this happens, it is slated to orbit the Sun for the next several million years.
What new discoveries about the Sun’s helicity barrier will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!