Bow shock wave
Bow shock wave with a diameter of about half a light year within the comparatively dense interstellar matter of the Orion Nebula , caused by the collision with the stellar wind of the star LL Orionis
As a bow shock (also bow shock , English bow shock ) is in astronomy the curved shock front denotes that arises when a plasma stream to an astronomical object ( "obstacle") meets and is decelerated from over- to subsonic speed. The plasma is compressed and heated up. If, on the other hand, a plasma stream hits an obstacle at subsonic speed, only a bow wave can occur - the plasma is then simply pushed aside.
Such a bow shock wave can occur, for example:
- in the interaction of the solar wind with the magnetosphere of a planet, e.g. B. Earth or Jupiter ;
- in the interaction of the solar wind with the coma of a comet ;
- in the interaction of interstellar gas with stellar wind (see astrosphere ) . Above all, this also applies to high-speed runners (runaway stars) who move through the interstellar medium at high speed. An example of this is Zeta Ophiuchi .
Contrary to earlier assumptions, there is probably no bow shock wave in the solar system in front of the heliosphere , since the relative speed of the sun to the surrounding interstellar medium is subsonic.
Individual evidence
- ↑ Lexicon of Physics. Spectrum of Science , accessed March 19, 2018 .
- ↑ Benjamin Knispel: Heliosphere. The discovery of slowness. In: ASTROnews. May 11, 2012 , Retrieved May 14, 2012.