It is worth pointing out that Li et al. (2014a) detected two jet-like features in HST images obtained on 2013 October 29, 2014 January 21, and 2014 March 11, which therefore support the application of the RJM. The RJM with one jet does not work well, e.g., χ 2 is worse than that obtained with the Marsden et al. (1973) model. This behavior is somehow expected: as the comet moves around the Sun the latitude of the sub-Solar point changes and at some point the jet gets confined in the comet’s shadow for the full rotation period, thus turning off the corresponding nongravita- tional accelerations. A possible refinement to the single jet model is obtained by adding A$_{1}$ , so that A$_{1}$ gives the main nongravitational perturbation in the radial direction while the jet mostly contributes to the other components. This configuration results in a significantly lower χ 2 value and the σ shift is 3.2, which is perfectly reasonable in an 11-dimensional parameter space (there is a 51% probability that Δ χ 2 > 3 . 2 with eleven degrees of freedom). The improvement obtained by adding A$_{1}$ warrants the addition of a sec- ond jet to the model. After all, using two jets is a sort of generalization of the one jet + A$_{1}$ solution. The orbital fit statistics and the σ shifts of these two models are essentially equivalent. Further adding A$_{1}$ to the two jets solution does not provide any improve- ment, thus suggesting that a third jet is not needed. On the other hand, the inclusion of the diurnal lag angle θ lowers χ 2 by 13 with respect to the best-fit two jets solution, which is a significant change for the addition of a single 25