Thermal fatigue plot. The thermal parameter (Θ) over heliocentric distance (r_h) for Phaethon (solid lines, r_h ≥ 0.14 au) and fiducial perpendicular model asteroids with varying r_h (dashedlines) are shown. The black star and plus symbols indicate that Γ is fixed, while the green triangle and cross markers show results where Γ is assumed to be changed by Eq. (20). The blue solid lines are the contours of , and the brown dashed lines are that of . The values shown for the contours are the and values for the case when c_T = 1 and P_rot = 1 h. The contours get thicker for larger values to guide the eyes.