Fig. 5: Periodograms of four spot tracers on XX Tri.
From: Long-term Doppler imaging of the star XX Trianguli indicates chaotic non-periodic dynamo
The top set of lines is from a phase dispersion minimization given in units of its normalized variance (right axis); the bottom set of lines is from the generalized Lomb-Scargle approach given in units of \(1-{\chi }^{2}/{\chi }_{0}^{2}\) (left axis). The color of the lines indicates the tracer: disk-integrated relative flux (black; data shown in Fig. 3c), photocenter offset (red; data shown in Fig. 4b), spot-filling factor (gray; data shown in Fig. 3b), and effective temperature (blue; data shown in Fig. 3a). Indicated are the rotation period P(rot) at 24 d and the only significant long period at 1514 d from the effective temperature. Source data are provided as a Source Data file.
