Related Experiment Video
Updated: Nov 7, 2025
10:04
Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
Published on: May 26, 2014
13.1K
3D simulations of oxygen shell burning with and without magnetic fields
Vishnu Varma1, Bernhard Müller1
1School of Physics and Astronomy, 10 College Walk, Monash University, Clayton VIC 3800, Australia.
Monthly Notices of the Royal Astronomical Society
|May 3, 2021
Summary
This study simulates magnetic field generation during oxygen and neon shell burning in stars. Magnetic fields approach saturation but do not significantly alter convective flow, though they do inhibit neon entrainment.
Area of Science:
- Astrophysics
- Computational Physics
- Stellar Evolution
Background:
- Supernova progenitors undergo convective burning in oxygen and neon shells before core collapse.
- Understanding magnetic field generation in these shells is crucial for supernova physics.
Purpose of the Study:
- To perform the first 3D magnetohydrodynamic (MHD) simulation of convective oxygen and neon shell burning.
- To investigate magnetic field generation and its impact on convective flow and mixing in pre-supernova stars.
Main Methods:
- A 3D MHD simulation of convective oxygen and neon shell burning in a non-rotating star.
- A comparative purely hydrodynamic simulation to isolate magnetic field effects.
- Analysis of magnetic field strength, scale, and stress tensor components.
Main Results:
- Magnetic fields approach saturation in the oxygen shell (average [Formula: see text]) but do not reach kinetic equipartition.
- The field is dominated by small-to-medium scales, with a weak dipole component ([Formula: see text]).
- Shear flow at the O-Ne interface generates fields that inhibit neon entrainment, slightly slowing convective flow.
Conclusions:
- Magnetic fields generated during shell burning do not significantly alter the internal convective flow.
- Inhibition of neon entrainment by magnetic fields has indirect effects on energy generation and flow speed.
- Further research with longer simulations and higher resolution is needed to fully understand magnetic field roles in supernova progenitors.
More Related Videos
07:24Combustion Chemistry of Fuels: Quantitative Speciation Data Obtained from an Atmospheric High-temperature Flow Reactor with Coupled Molecular-beam Mass Spectrometer
Published on: February 19, 2018
10.3K
09:40Electron Spin Resonance Micro-imaging of Live Species for Oxygen Mapping
Published on: August 26, 2010
22.6K
Related Concept Videos
01:27Magnetic Fields
6.6K
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
6.6K
01:23Atomic Nuclei: Nuclear Relaxation Processes
871
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
871
01:19Magnetic Field Lines
4.8K
The representation of magnetic fields by magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Each of the magnetic field lines forms a closed loop. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.
Magnetic field lines follow several hard-and-fast rules:
Magnetic field lines follow several hard-and-fast rules:
4.8K
01:14Diamagnetic Shielding of Nuclei: Local Diamagnetic Current
1.1K
An applied magnetic field causes the electrons present in the molecule to circulate, setting up a local diamagnetic current within the molecule. The local diamagnetic current arising from circulating sigma-bonding electrons induces a magnetic field, Blocal that opposes the applied magnetic field, B0. The effective magnetic field experienced by these nuclei is given by the difference between the applied and local magnetic fields in a phenomenon called local diamagnetic shielding. Essentially,...
1.1K
01:24Energy In A Magnetic Field
2.4K
If a magnetic field is sustained, there must be a current in a closed circuit or loop, implying some energy has been spent in creating the field. If this energy is not dissipated via the circuit's resistance, it is stored in the field.
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus...
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus...
2.4K
01:28Magnetostatic Boundary Conditions
1.4K
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
1.4K