The astrophysicists of the French CNRS have recently defined the limit of the solar system. 100 astronomical units or 15 billion kilometers.
The heliopause separates the heliosphere (i.e. the Sun and the surrounding solar wind) from the interstellar cloud formed by neutral and plasma particles.
The heliosphere that circulates through the local cloud of Izarra is somehow cleaned by a gas wind (interstellar wind). Although interstellar plasma prevents heliopause, neutral particles (especially hydrogen atoms) can pass through it.
Analyzing the characteristics of hydrogen on the one hand and the heliopause on the other, the deceleration of hydrogen indicates the influence of the heliosphere. Interstellar plasma density, which should be between 0.6 and 0.10 protons per cubic centimeter, can also be measured. This density is sufficient to maintain the solar wind in a heliosphere that does not reach a hundred astronomical units.