Stellar mass loss

Stellar mass loss

Stellar mass loss is a phenomenon observed in some massive stars. It occurs when a triggering event causes the ejection of a large portion of the star's mass. Stellar mass loss can also occur when a star gradually loses material to a binary companion or into interstellar space.

Causes

A number of factors can contribute to the loss of mass in giant stars. A few are listed below:
*Gravitational attraction of a binary companion
*Coronal mass ejection-type events
*Ascension to red giant or red supergiant status

Gravitational Mass Loss

Often when a star is a member of a pair of close-orbiting binary stars, the tidal attraction of the gasses near the center of mass are sufficient to pull gas from one star onto its partner. This effect is especially prominent when the partner is a white dwarf, neutron star, or black hole.

Mass Ejection

Certain classes of stars, especially Wolf-Rayet stars are sufficiently massive and distended that their hold on their upper layers is rather weak. Often, events such as solar flares and coronal mass ejections will then be sufficiently powerful to blast some of the upper material into space.

Red Giant Mass Loss

Stars which have entered the red giant phase are notorious for rapid mass loss. As above, the gravitational hold on the upper layers is weakened, and they may be shed into space by violent events such as the beginning of a helium flash in the core. The final stage of a red giant's life will also result in prodigious mass loss as the star loses its outer layers to form a planetary nebula.

ee also

*red giant
*red supergiant
*coronal mass ejection
*helium flash
*second ascension

External links

* [http://www.astro.uu.se/~bf/movie/dst35gm04n26/rsgintro_en.html| Simulation of a Red Supergiant displaying instability and mass loss]

References

*Seeds, Michael A., "Astronomy: The Solar System and Beyond", Brooks/Cole 2005


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Stellar rotation — is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface.The rotation of a star produces an equatorial bulge due to… …   Wikipedia

  • Stellar evolution — Life cycle of a Sun like star Stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. Depending on the mass of the star, this lifetime ranges from only a few million years (for the most… …   Wikipedia

  • Mass–luminosity relation — In astrophysics, the mass–luminosity relation is an equation giving the relationship between a star s mass and its luminosity. The relationship is represented by the equation: where L⊙ and M⊙ are the luminosity and mass of the sun and… …   Wikipedia

  • Stellar wind — A stellar wind is a flow of neutral or charged gas ejected from the upper atmosphere of a star. It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally… …   Wikipedia

  • Mass segregation — In astronomy, dynamical mass segregation is the process by which heavier members of a gravitationally bound system, such as a star cluster or cluster of galaxies, tend to move toward the center, while lighter members tend to move farther away… …   Wikipedia

  • Coronal mass ejection — A coronal mass ejection in time lapse imagery obtained with the LASCO instrument. The Sun (center) is obscured by the coronagraph s mask. (September 30 – October 1, 2001) A coronal mass ejection (CME) is a massive burst of solar wind, other light …   Wikipedia

  • Supergiant — Supergiants are among the most massive stars. In the Hertzsprung Russell diagram they occupy the top region of the diagram. In the Yerkes spectral classification supergiants are class Ia (most luminous supergiants) or Ib (less luminous… …   Wikipedia

  • cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… …   Universalium

  • Star — For other uses, see Star (disambiguation) …   Wikipedia

  • White dwarf — For other uses, see White dwarf (disambiguation). Image of Sirius A and Sirius B taken by the Hubble Space Telescope. Sirius B, which is a white dwarf, can be seen as a faint pinprick of light to the lower left of the much brighter Sirius A …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”