Kippenhahn diagrams showing the evolution of the structure (in Eulerian coordinates) as a function of time (Myr) for the lowest-mass models. The blue and cream regions represent the convective and radiative zones, respectively. The iso-masses are depicted by black lines, whereas the isotherms of log(T[K]) = 5, 6, 7, and 8 are drawn in white lines. The translucent yellow regions show deuterium burning; dotted dark grey zones are hydrogen burning zones; and the dark grey zone highlights helium burning.