Credit: Queen Mary University of London
Researchers have actually verified the presence of magnetic plasma waves, referred to as Alfvén waves, in the Sun’s photosphere.
The research study, released in Nature Astronomy, supplies brand-new insights into these remarkable waves that were very first found by the Nobel Prize winning researcher Hannes Alfvén in 1947.
The huge capacity of these waves lives in their capability to transfer energy and info over large ranges due to their simply magnetic nature. The direct discovery of these waves in the solar photosphere, the most affordable layer of the solar environment, is the initial step towards making use of the residential or commercial properties of these magnetic waves.
The capability for Alfvén waves to bring energy is likewise of interest for solar and plasma-astrophysics as it might assist describe the severe heating of the solar environment — a secret that has actually been unsolved for over a century.
Elusive waves
Alfvén waves form when charged particles (ions) oscillate in action to interactions in between electromagnetic fields and electrical currents.
Credit: Queen Mary University of London
Within the solar environment packages of electromagnetic fields, referred to as solar magnetic flux tubes, can form. Alfvén waves are though to manifest in one of 2 types in solar magnetic flux tubes; either axisymmetric torsional perturbations (where symmetric oscillations happen around the flux tube axis) or anti-symmetric torsional pertubations (where oscillations happen as 2 swirls turning in opposite instructions in the flux tube).
Despite previous claims, torsional Alfvén waves have actually never ever been straight recognized in the solar photosphere, even in their easiest type of axisymmetric oscillations of magnetic flux tubes.
In this research study, the scientists utilized high-resolution observations of the solar environment, made by the European Space Agency’s imager IBIS, to show the presence of anti-symmetric torsional waves initially forecasted nearly 50 years earlier.
They likewise discovered that these waves might be utilized to draw out huge quantities of energy from the solar photosphere, verifying the capacity of these waves for a wide variety of research study locations and commercial applications.
The research study was led by Dr. Marco Stangalini, Italian Space Agency (ASI, Italy) and researchers from 7 other research study institutes and universities, consisting of Queen Mary’s Dr. David Tsiklauri and PhD trainee Callum Boocock, were associated with this groundbreaking discovery.
State-of-the art simulations
In addition to these observations, scientists at Queen Mary carried out mathematical simulations to check out the excitation systems of these evasive waves.
The Queen Mary scientists created and established a magnetohydrodynamic (MHD) simulation, which is utilized to design the characteristics of allured fluids like those discovered in the solar environment, to recreate the group’s observations.
Dr. David Tsiklauri, Visiting Senior Lecturer at Queen Mary’s School of Physics and Astronomy, stated: “What was amazing is that our idea that linearly polarized Alfvén Wave driving at the bottom of a magnetic flux tube will result in the generation of torsional oscillations in the entire flux tube held true for a wide range of physical parameters. Both observations and simulations were signalling the discovery of Alfvén waves.”
Callum Boocock, a PhD trainee at Queen Mary’s School of Physics and Astronomy, stated: “The observations of torsional Alfven waves made by Marco and his team were remarkably similar to the behaviour seen in our MHD simulations, demonstrating the importance of these simulations for discovering and explaining wave generation mechanisms.”
The scientists want to have the ability to utilize brand-new chances provided by just recently commissioned centers, such as the Solar Orbiter satellite and the ground-based Daniel K. Inouye Solar Telescope (DKIST), to continue to look into the importance of Alfvén waves and possibly additional reveal the essential tricks of the Sun.
Reference: “Torsional oscillations within a magnetic pore in the solar photosphere” by Marco Stangalini, Robertus Erdélyi, Callum Boocock, David Tsiklauri, Christopher J. Nelson, Dario Del Moro, Francesco Berrilli and Marianna B. Korsós, 10 May 2021, Nature Astronomy.
DOI: 10.1038/s41550-021-01354-8
The research study was supported by moneying from the Science and Technology Facilities Council (STFC).
