Propose a solution to the mystery of the incredibly strong white dwarf magnetic field

Map of the origin of the magnetic field in the white dwarf in the shut binary file (learn counterclockwise). When the crystalline white dwarf is drawn from the companion star, the magnetic field will seem, and as a outcome, it should start to spin quickly. When the white dwarf field is linked to the field of the secondary star, the mass switch will cease in a comparatively brief time. Image credit score: Paula Zorzi

  • Warwick University New analysis co-authored by astronomers Natural astronomy Proposed options to long-standing issues white dwarf Stars produce magnetic fields
  • A generator mechanism comparable to how the earth generates a magnetic field could also be the reply
  • This analysis exhibits that typically very comparable mechanisms can work in very totally different astronomical objects.

According to a world crew of scientists together with astronomers at the University of Warwick, the generator mechanism can clarify the incredibly strong magnetic field in white dwarfs.

One of the most putting phenomena in astrophysics is the existence of magnetic fields. Like the Earth, there may be additionally one star and stellar stays (comparable to a white dwarf). As everyone knows, the magnetic field of a white dwarf could also be a million occasions stronger than that of the Earth. However, since the first magnetic white dwarfs had been found in the Seventies, their origins have been a mystery. Several theories have been proposed, however none of them can clarify the totally different incidence of magnetic white dwarfs as a single star and in several binary star environments.

Thanks to the analysis of a world crew of astrophysicists, together with Professor Boris Gänsicke from the University of Warwick and Dr. Matthias Schreiber from Núcleo Milenio de Formación Planetaria from Universityidad Santa María, Chile. The analysis crew confirmed that a generator mechanism comparable to the magnetic field on the Earth and different planets can work in white dwarfs and produce stronger magnetic fields.This analysis was partially funded by the Science and Technology Facilities Committee (STFC) and the Leverhulme Trust and has been printed in a prestigious scientific journal Natural astronomy.

Crystalline Magnetic White Dwarf

A crystalline magnetic white dwarf star drawn from the wind of its companion star. Image credit score: Paula Zorzi

Boris Gänsicke, a professor in the Department of Physics at the University of Warwick, stated: “For a long time, our understanding of the magnetic field of white dwarfs has been lacking, because the statistics obtained from observations are not meaningful. At least some of them. In stars, the idea that the magnetic field is generated by a generator can solve this paradox. Some of you may remember the generator on a bicycle: rotating a magnet produces an electric current. Here, it works in the opposite way, the material is Motion generates electric current, and electric current generates magnetic field.”

According to the proposed generator mechanism, the magnetic field is generated by the present generated by the convective movement in the core of the white dwarf. These convections are attributable to the warmth dissipated by the solidified core.

“The foremost element of a generator is a stable core surrounded by a convective mantle-for the Earth, it’s a cast-iron core surrounded by convective liquid iron. Matthias Schreiber defined that when the white dwarf is sufficiently cooled, a comparable scenario can occur.

Astrophysicists defined that in the starting, after the star ejected its outer shell, the white dwarf was extremely popular and consisted of liquid carbon and oxygen. However, when it cooled sufficiently, it started to crystallize in the middle, and its construction turned comparable to that of the earth: a stable core surrounded by convective liquid. “Because the speed of the liquid in a white dwarf may be much higher than that on Earth, the magnetic field generated may be stronger. This generator mechanism can explain the incidence of strong magnetic white dwarfs in many different situations, especially in binary stars. The incidence of white dwarfs,” he stated.

Therefore, this analysis can resolve a long time of issues. “The beauty of our ideas is that the mechanism of magnetic field generation is the same as that of planets. This study explains how magnetic fields are generated in white dwarfs and why these magnetic fields are much stronger than those on Earth. I think this is a good example. Explain how interdisciplinary teams can solve problems that experts in only one field may encounter,” Schreiber added.

Astrophysicists say that the subsequent step on this analysis is to implement a extra detailed mannequin of the generator mechanism and to check the different predictions of the mannequin observationally.

Reference: Matthias R. Schreiber, Diogo Belloni, Boris T. Gänsicke, Steven G. Parsons and Monica Zorotovic, “The Origin and Evolution of Magnetic White Dwarfs in Parent Stars”, April 29, 2021, Natural astronomy.
DOI: 10.1038 / s41550-021-01346-8

The analysis was additionally supported by the STFC Ernest Rutherford Scholarship.