Light curve evolution of M 81*. Top panel: Position angle measurements alongside the best-fit model (Eq. (1)). Lower panel: 5 GHz light curve of M 81*. The black lines indicate the data extracted from Martí-Vidal et al. (2011) and Alberdi et al. (2013), and the orange pentagon denotes our newest measurement. The gray line shows a best-fit Gaussian model, which approximates the observed flare. The vertical line indicates the peak of the Gaussian flare model. The Gaussian flare shape is shifted by the precession period (6.9 yr).