Definition of heliopause in US English:

heliopause

noun

Astronomy
  • The boundary of the heliosphere.

    • ‘Its last assignment was to find the heliopause, where the solar wind is offset by the galactic wind, but in April 1997 it was passed by a younger, faster Voyager spacecraft.’
    • ‘Electromagnetic propulsion could take us to the heliopause at a speed unachievable by conventional spacecraft.’
    • ‘The fact that a man-made object is now approaching the heliopause, where the solar winds cease to blow, is a remarkable achievement.’
    • ‘In a small side article, she notes that NASA's Voyager 2 spacecraft has passed the heliopause, the outermost edge of our solar system.’
    • ‘That includes two Voyager probes looking for the heliopause, where true interstellar space begins.’
    • ‘Both Voyagers are headed towards the outer boundary of the solar system in search of the heliopause, the region where the Sun's influence wanes and the beginning of interstellar space can be sensed.’

Pronunciation

heliopause

/ˈhēlēəˌpôz/