Solar System Physics at Aberystwyth University

The research interests of the Solar System Physics group at Aberystwyth University include the Sun, the Sun's atmosphere, the solar wind, space weather, planetary science, and astronomical instrumentation. Our research spans important aspects of our solar system, and our study of these environments leads to progress in physics and astronomy, direct benefits to society in understanding the hazards of space weather, and other indirect benefits through cross-disciplinary research.

Our understanding of the Sun is surprisingly incomplete. A strong magnetic field permeates the Sun's visible surface (the photosphere), and dictates the structure of the atmosphere. This is the corona - a hot, magnetised plasma, an interesting environment for physics. Understanding this environment, through observation and models, drives progress on fundamental plasma physics, and leads to the ability to predict solar storms. Models of this complex system remain incomplete or untested, thus many aspects remain unexplained. With recent (and near-future) advancements in observation, solar physics is on the verge of answering some of these questions. Our research plays an important part in this effort.

A large part of our research is dedicated to the development of new data analysis tools that reveal and characterise solar atmospheric events and phenomena. For the first time, we are able to calcuate the true 3D structure of the extended corona, a success which can greatly advance the field of linking the solar atmosphere to the outflow of plasma in interplanetary space called the solar wind. This provides a powerful new diagnostic that will constrain models and enable an improved mapping of the complex coronal magnetic field.

Using large new ground-based telescopes, we study the light emitted by magnetic structures in the corona in order to estimate their physical properties such as magnetic field strength, temperature, and density. We recently discovered that the magnetic field in a coronal loop structure was far higher than previously expected. Since the magnetic field strength is one of the most important properties controlling the structure and dynamics of the corona, this result is very important and demands further study.

The magnetic field of the solar atmosphere is being constantly moved and twisted by motions at the photosphere. These motions drive a gradual increase in stored magnetic energy, as the field is being constantly driven into complicated configurations. In active regions above sunspots, where the magnetic field is most intense, the field can suddenly reconfigure, or 'reconnect' - a catastrophic event that rapidly heats the plasma to several million degrees, and leads to bursts of highly-accelerated electrons and protons, and the ejection of a large magnetised plasma cloud. These are called flares and coronal mass ejections (CMEs). These can cause disruption to our technology in space and on Earth, and danger to astronauts. An important element of our work seeks to improve the prediction of these events, and this proposal describes work that derives several promising data products for prediction, and the use of machine learning algorithms for prediction.