Extending Zeeman-Doppler Imaging to Pulsating Magnetic Stars

Zeeman-Doppler Imaging (ZDI) is a technique that inverts a series of spectropolarimetric data allowing the reconstruction of stellar magnetic fields, which provides valuable insights into their strength, geometries, and time evolution. However, ZDI assumes that stellar line profile variations are due solely to rotation - an assumption that breaks down for pulsating stars, where oscillations introduce additional Doppler shifts. By modelling the pulsation modes identified with spectroscopic/spectropolarimetric and photometric observations,
we can create a time-dependent surface velocity map which accounts for all causes of Doppler shifts of local lines. This allows the causes of line profile variations associated with rotation, i.e. magnetic fields and spots, to be accurately assigned locations on the stellar surface preventing errors in the magnetic field strength and geometry ; and spot locations, relative brightness, and sizes. This is crucial for obtaining the correct stellar
and magnetic properties.