  From 1975 to 1976, an outburst was detected in the light curve of the X-ray
transient A0620-00 using the Ariel V and SAS-3 experiments. In this letter we
model the outburst with the hydrodynamical model proposed by Mendoza et al.
(2009). The physical model is constructed assumming basic mass and momentum
conservation laws associated to the motion of the shock waves developed inside
the expanding relativistic jet of the source. These internal shock waves are
produced as a result of periodic variations of the inyected mass and velocity
of the flow at the base of the jet. The observations of this X-ray light curve
present two clear bumps. The first one is modelled assuming periodic variations
of the inyected velocity at the base of the jet, while the second one can
either be modelled by a further velocity oscillations, or by a periodic
variation of the mass injection rate at the base of the jet at a latter time.
The fitting of the data fixes different parameters of the model, such as the
mean mass injection rate at the base of the jet and the oscillation frequency
of the flow as measured on the rest frame of the central source.
