Stellar-wind bubble

 ( Stellar Astronomy ) 

A stellar-wind bubble is a cavity across filled with hot gas blown into the interstellar medium by the high-velocity (several thousand km/s) stellar wind from a single massive star of type O-type star or B. Weaker stellar winds also blow bubble structures, which are also called astrospheres. The heliosphere blown by the solar wind, within which all the major of the Solar System are embedded, is a small example of a stellar-wind bubble.

Stellar-wind bubbles have a two-shock structure. The freely-expanding stellar wind hits an inner termination shock, where its kinetic energy is thermalized, producing 10⁶ kelvin, X-ray-emitting plasma. The hot, high-pressure, shocked wind expands, driving a shock into the surrounding interstellar gas. If the surrounding gas is dense enough (number densities $n\; >\; 0.1\; \backslash mbox\{\; cm\}^\{-3\}$ or so), the swept-up gas radiatively cools far faster than the hot interior, forming a thin, relatively dense shell around the hot, shocked wind.

• Cosmic wind
• Stellar wind
• Solar wind
• Planetary wind
• Colliding-wind binary
• Pulsar wind nebula
• Galactic superwind
• Superwind