Multifrequency data of the core position angle of M 81*. The black points indicate the 5 GHz position angle as presented by Martí-Vidal et al. (2011), and the orange pentagons show the new 2018 and 2019 measurements. The black line with gray contours (1σ, 2σ, and 3σ) shows the best fit to all 5 GHz data. The brown points show the 1.7 GHz data; the brown line shows the best fit to the 5 GHz data, shifted by 1.9 yr, as suggested by Martí-Vidal et al. (2011). The green points show the 8 GHz measurement; the green line shows the best-fit 5GHz model shifted by ∼ − 3.5 yr.