The Sun follows a solar cycle, which reflects magnetic activity, and different solar phenomena follow the solar cycle, such as sunspots and coronal mass ejections of super-hot plasma (a hot ionized gas). Also part of the cycle are solar wind, radio wave flux, energy bursts such as solar flares, and solar eruptions. It remains a mystery why the Sun has a predictable eleven-year cycle; however, researchers have recently been gaining new insights into the Sun’s cycle.
Terminator events
The new research has identified how solar cycles can trigger a tsunami of hot plasma for such magnitude that the researchers how discovered these shifts have dubbed them ‘terminators’. They drew this information, Phys.org reports, by studying the Sun’s magnetic fields, spectral irradiance, radio flux and bright spots. The occurrence of this phenomenon signals that the solar cycle is coming to an end. Data was drawn from comprehensive solar observations from the Solar Terrestrial Relations Observatory (STEREO) and Solar Dynamics Observatory (SDO).
The study has been published in the journal Solar Physics, with the paper titled “What the Sudden Death of Solar Cycles Can Tell Us About the Nature of the Solar Interior.”
Solar tsunamis
A second study finds that the terminator events can sometimes “solar tsunamis”, according to Engadget. This occurs when the Sun’s magnetic fields move to the surface and form sunspots. This process traps plasma like a dam. On occasions when two fields meet, they interact and destroy each other. This process releases an intense wave of hot plasma, capable of moving at 300 meters per second creating the bright points on the surface referred to as sunspots.
Studying several events, the researchers noted how tsunamis are excited at the equator when magnetic dams, created by the oppositely-directed old cycle’s toroidal field in North and South hemispheres, break due to mutual annihilation of what is called ‘toroidal flux’. A toroidal field is a magnetic confinement system where plasma is kept stable by an externally generated magnetic field and by electric currents flowing within the plasma.
Commenting on the study, U.S. National Center for Atmospheric Research scientist Scott McIntosh states: “The evidence for terminators has been hidden in the observational record for more than a century, but until now, we didn’t know what we were looking for. By combining such a wide variety of observations over so many years, we were able to piece together these events and provide an entirely new look at how the Sun’s interior drives the solar cycle.”
The research is published in Nature Scientific Reports, with the paper headed “Triggering The Birth of New Cycle’s Sunspots by Solar Tsunami.”
When stars die
As to what will happen to the Sun when it dies, in another study, scientists have discovered a dust grain forged in a stellar explosion before our solar system was born. Subjecting this to atom-level analysis has revealed new insights into how stars end their lives and go on to seed the universe with the building blocks for new stars and planets. This research has been published in Nature Astronomy (“Laboratory evidence for co-condensed oxygen- and carbon-rich meteoritic stardust from nova outbursts”).
