[ hee-lee-uh-pawz ]
/ ˈhi li əˌpɔz /

noun Astronomy.

the boundary of the heliosphere.

Origin of heliopause

First recorded in 1970–75; helio- + pause
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for heliopause


/ (ˈhiːlɪəʊˌpɔːz) /


the boundary between the region of space dominated by the solar wind and the interstellar medium
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for heliopause


[ hēlē-ə-pôz′ ]

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. See more at solar wind.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.