Generality of the Temp–magnetic-field anticorrelation beyond AU Mic

Establish whether the strong anticorrelation between the disk-averaged temperature indicator (Temp) and the small-scale magnetic field <B> observed for the active M dwarf AU Mic also holds for stars that are much less active and across different effective temperatures.

Background

Using SPIRou near-infrared spectra and the proposed line-by-line temperature-gradient method, the authors derive a time series of the disk-averaged temperature indicator (Temp) for AU Mic and find a strong anticorrelation with the independently measured small-scale magnetic field <B>.

They provide an empirical calibration linking Temp and <B> for AU Mic and argue that if this relation is general, Temp could serve as a powerful activity proxy for radial-velocity jitter mitigation. However, they explicitly state uncertainty about whether this anticorrelation extends to less active stars and to different stellar effective temperatures, leaving this as future work.