Post-fit residuals from the modeling of TVLM 513 flare arrival times. (a) A fit for phase with a fixed period and its time derivatives set to zero. Vertical arrows mark the two phase jumps. The sloping lines denote the best fits to subsets of data made for the purpose of period measurement. (b) Post-fit residuals from the model including phase, period, its first time derivative, and the two phase jumps. The solid and the dashed lines compare the fits of these residuals with the circular, 162 day orbit and the second derivative of the period, respectively. (c) A fit for phase, period, its first two time derivatives and the phase jumps. Triangles mark the data points obtained from flares shown in Figure 1.