heliopause

[ hee-lee-uh-pawz ]

noun

, Astronomy.

1. the boundary of the heliosphere.

heliopause

/ ˈhiːlɪəʊˌpɔːz /

noun

1. the boundary between the region of space dominated by the solar wind and the interstellar medium

heliopause

/ hē′lē-ə-pôz′ /

1. The region surrounding the solar system at which pressure from the outgoing solar wind equals the pressure from the interstellar medium (made up mostly of hydrogen and helium), and the solar wind can penetrate no further. It is considered to be the outer boundary of our solar system.
2. See more at solar wind

Word History and Origins

Origin of heliopause¹

First recorded in 1970–75; helio- + pause

Example Sentences

What seems to be happening, McComas explained, is that a fraction of the charged particles that were part of the solar wind, and are now neutralized, are propagating radially out, past the heliopause into the local interstellar medium.

From Nautilus