Magnetic helium-rich hot subdwarfs star found with Southern African Large Telescope

 

Here the magnetic field was detected 200kG which is detected based on the zeeman effect. 

Zeeman effect: In zeeman effect, magnetic field distorts electron orbitals, which affects atomic energy levels and the transitions between them. This results in the splitting of atomic energy levels in a molecule, which in turn splits the spectral lines.

The splitting of a spectral line in the presence of a magnetic field is given by

Surface gravity is given by

Effective temperature is calculated based on 

The radial velocity is calculated using the Doppler effect equation:

Δλ = observed wavelength shift .

λ0 = rest wavelength of the spectral line

Galactic space velocities for the confirmed magnetic He-sdOs are calculated from their radial velocity.

Magnetic fields can cause dark or bright spots on a star’s surface, resulting in variations in brightness as the star rotates

Here the Hertzsprung-Russell diagram is used to compare the magnetic He-sdO stars with non-magnetic hot subdwarfs and other stars based on their temperature, luminosity, and mass.  

In the article, the mass of the magnetic He-sdO stars is estimated based on their location relative to the helium main sequence. The mass is interpolated from their position on the diagram.

When stars plot the same region of the H-R diagram, it indicates that they likely formed through a specific and same process.

Reference: https://arxiv.org/abs/2410.02737