Irene Amateis: Measuring magnetic field strengths in M dwarfs (Licentiate defence)

Monday 19 Oct 2026, 13:15 → 14:15 Europe/Stockholm

Å4006

Title: Measuring magnetic field strengths in M dwarfs (Licentiate defence) 
Speaker: Irene Amateis
Affiliation: Uppsala University
Room: Å4006
Time: 13:15-15:00

Abstract:
M dwarfs are the most common stars in the Galaxy and important targets in the search for potentially habitable exoplanets. Their strong magnetic fields shape stellar atmospheres and influence the environments
of their orbiting planets, making reliable magnetic field measurements essential.
This licentiate thesis investigates the reliability of magnetic field measurements in M dwarfs using Zeeman broadening in high-resolution spectra. By testing commonly used diagnostic methods against synthetic
spectra generated from magnetohydrodynamic simulations, we show that some methods can underestimate magnetic field strengths by up to 50%, while alternative approaches provide a more accurate recovery of the true field strength. These results establish quantitative benchmarks
for interpreting magnetic field measurements from intensity spectra and highlight important limitations of commonly used diagnostics. As a next step, the most reliable methods will be applied to observations of M dwarfs obtained with the CRIRES+ spectrograph
at the VLT.

 

The external reviewer is Alexis Brandeker (Stockholm University)