The outer portion of the Sun that extends to the heliopause is called the heliosphere.

Here's a breakdown:

* Sun: Our star, the center of our solar system.

* Solar wind: A stream of charged particles constantly flowing outwards from the Sun.

* Heliosphere: The bubble-like region of space created by the solar wind. It extends far beyond the orbit of Pluto, encompassing all the planets in our solar system.

* Heliopause: The boundary where the solar wind collides with the interstellar medium (the gas and dust between stars), marking the end of the heliosphere.

So, to summarize: the Sun's outer portion extends outwards through the heliosphere until it reaches the heliopause.