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Stellar Wind

Mass Loss

The single most important property affecting the evolution of a star is its mass. Therefore when the stellar wind causes a star to lose mass, its evolution is affected. In some cases these effects are still poorly understood. One reasonably well understood effect occurs for red giants collapsing into white dwarfs as described above. A star having more than 1.4 times the mass of the sun can not collapse into a stable white dwarf. Stars that exceed this mass limit collapse into neutron stars or black holes. Stellar winds can cause red giants with masses up to about 8 times the mass of the sun to lose enough mass to collapse into a white dwarf having less than 1.4 times the mass of the sun.

Roughly half of all stars occur in binary systems. When a star in a binary system has a stellar wind it loses mass. Some of this mass is transferred to the other star in the system, so it gains mass. Hence the mass of both stars in the system changes when one of the stars has a stellar wind. The evolution of both stars in the system is affected.

Resources

Books

Bacon, Dennis Henry, and Percy Seymour. A Mechanical History of the Universe. London: Philip Wilson Publishing, Ltd., 2003.

Morrison, David, Sidney Wolff, and Andrew Fraknoi. Abell's Exploration of the Universe. 7th ed. Philadelphia: Saunders College Publishing, 1995.

Periodicals

Frank, Adam. "Winds of Change." Discover (June 1994): 100-104.

Van Buren, David. "Bubbles in the Sky." Astronomy (January, 1993): 46-49.

Paul Heckert

KEY TERMS

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Interstellar medium: —The matter between the stars.
O stars: —The hottest most massive stars when classified on the basis of the star's spectrum..
Planetary nebula: —A shell of hot gas surrounding a star in the late stages of its evolution.
Red giant: —An extremely large star that is red because of its relatively cool surface.
Solar wind: —A stream of charged and neutral particles that emanates from the Sun and moves into the solar system.
Stellar wind: —A stream of particles blowing out from a star.
T Tauri star: —An early stage in the evolution of stars like the sun.
White dwarf: —A star that has used up all of its thermonuclear energy sources and has collapsed gravitationally to the equilibrium against further collapse that is maintained by a degenerate electron gas.
Wolf-Rayet star: —A very hot energetic star that ejects a shell of gas.

Additional topics

Science EncyclopediaScience & Philosophy: Spectroscopy to Stoma (pl. stomata)Stellar Wind - Solar Wind, Massive Hot Stars, Baby Stars, Dying Stars, Mass Loss - Stellar winds