Models for velocity decrease in HH34

The conservation of the energy flux in turbulent jets that propagate in the interstellar medium (ISM) allows us to deduce the law of motion when an inverse power law decrease of density is considered. The back-reaction that is caused by the radiative losses for the trajectory is evaluated. The velocity dependence of the jet with time/space is applied to the jet of HH34, for which the astronomical data of velocity versus time/space are available. The introduction of precession and constant velocity for the central star allows us to build a curved trajectory for the superjet connected with HH34. The bow shock that is visible in the superjet is explained in the framework of the theory of the image in the case of an optically thin layer.