limb darkening

In astrophysics, the gradual decrease in observed brightness of the disk of a star from its centre to its edge (limb).

This phenomenon, readily apparent in photographs of the Sun, occurs because the solar atmosphere's temperature increases with depth. Looking at the Sun's centre, an observer sees the deepest, hottest layers, which emit the most light. At the limb, only the upper, cooler layers, which produce less light, are visible. Observations of solar limb darkening are used to determine the temperature structure of the Sun's atmosphere.

* * *

      in astrophysics, gradual decrease in brightness of the disk of the Sun or of another star as observed from its centre to its edge, or limb. This phenomenon is readily apparent in photographs of the Sun. The darkening is greatest for blue light, amounting to a drop of as much as 90 percent from the Sun's photosphere to its outer atmospheric regions. Such limb darkening occurs because the solar atmosphere increases in temperature with depth. At the centre of the solar disk, an observer sees the deepest and warmest layers that emit the most light. At the limb, only the upper, cooler layers that produce less light can be seen. Observations of solar limb darkening are used to determine the temperature structure of the Sun's atmosphere. Information derived from such observations is applied in studying other stars.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Limb darkening — refers to the diminishing of intensity in the image of a star as one moves from the center of the image to the edge or limb of the image. Limb darkening occurs as the result of two effects:* The density of the star diminishes as the distance from …   Wikipedia

  • Darkening — may refer to: Darkening (ophthalmology), vision loss or weakness that occurs without an apparent lesion affecting the eye Darkening of Valinor, the destruction of the Two Trees of Valinor in in the fictional universe of J. R. R. Tolkien s Middle… …   Wikipedia

  • Limb — can have many meanings. ten thousand to be precise.*from the Old English lim : **Limb (anatomy), a limb is a jointed or prehensile appendage of the human or animal body **a large or main branch of a tree. **In social structure, a representative,… …   Wikipedia

  • Gravitational microlensing — Gravitational Lensing Formalism Strong lensing …   Wikipedia

  • star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …   Universalium

  • sun — sunlike, adj. /sun/, n., v., sunned, sunning. n. 1. (often cap.) the star that is the central body of the solar system, around which the planets revolve and from which they receive light and heat: its mean distance from the earth is about 93… …   Universalium

  • Alpha Arietis — α Arietis α Arietis shown in its constellation, Aries. Observation data Epoch J2000.0      Equinox J2000.0 ( …   Wikipedia

  • Mariner 2 — Operator NASA Major contractors Jet Propulsion Laboratory Mission type Flyby …   Wikipedia

  • eclipse — eclipser, n. /i klips /, n., v., eclipsed, eclipsing. n. 1. Astron. a. the obscuration of the light of the moon by the intervention of the earth between it and the sun (lunar eclipse) or the obscuration of the light of the sun by the intervention …   Universalium

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

Share the article and excerpts

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

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.