Bow shock among c s Is the speed of sound, Is the ratio of isobaric heat capacity to isobaric heat rate, p Is the pressure, Is the density of the plasma. The charged particles in the solar wind follow the spiral track along the Magnetic line of force The motion around the magnetic field line is similar to the thermal motion in ordinary gases, and the average speed of thermal motion is approximately the speed of sound. At the bow shock, the overall velocity decreases below the velocity of particles around the magnetic field line. People imagine that the sun Interstellar medium The bow shock wave will also be formed during the middle motion. This assumption is based on the premise that the motion speed of the interstellar medium relative to the sun is supersonic, because solar wind It is blowing from the surface of the sun at supersonic speed. At the heliospheric top, the pressure between the interstellar medium and the solar wind reaches equilibrium termination shock It is reduced to subsonic speed. The location of the bow shock is about 230 away from the sun Astronomical unit 。 Herbie Arrow There are also bow shock waves around. Their bow shock waves can be observed in the visible light band due to the stronger interaction between their stellar winds and the interstellar medium.
