Magnetic field energies in the units of total heat (integrated over stellar material) as a function of time for the simulation BH 2. Black dots are total E^M, red crosses are ﹩{E}_{\varpi }^{{\rm{M}}}﹩, green triangles are ﹩{E}_{\varphi }^{{\rm{M}}}﹩, and blue crosses are ﹩{E}_{z}^{{\rm{M}}}﹩. The solid cyan line is an exponential fit to ﹩{E}_{z}^{{\rm{M}}}﹩ in the range 60 days < t < 150 days.