Home > Carbon star

Through spectral analysis, many carbon compounds have been detected at high levels, such as cyanogen and HCN. These compounds have circulated from the core of the star into its upper layers, dramatically changing the layers' composition. Other elements formed through helium fusion are also "kicked up" in this way, including lithium and zirconium. In "normal" stars (such as the Sun), whose atmospheres are rich in oxygen and relatively poor in carbon, the upper layers are conversely abundant in helium and nitrogen.

These late star s are cool, with typical surface temperatures ranging from 2000-3000 kelvin; they emit most of their energy in the form of infrared radiation with higher energies (i.e., the blueBlue (from Old High German "blao" shining) is one of the three primary additive colors; blue light has the shortest wavelength (about 470 nm) of the three primary colors. A clear sky on a sunny day is colored blue because of Rayleigh scattering of the lig part of the visible spectrum) being absorbed by the atmospheric carbon. Although very large, carbon stars are visibly dim and hard to spot without specialized equipment; the stars are a distinctly deep red or brown colour described as "smoky". All carbon stars are variable starMost stars are of nearly constant luminosity. Our own Sun is a good example of one which goes through relatively little variation in brightness (usually about 0. 1% over an 11 year solar cycle). Many stars, however, undergo significant variations in lumins, with irregularAn irregular variable is a type of variable star in which variations in brightness show no regular periodicity. There are two main sub-types of irregular variable eruptive irregular variables and pulsating irregular variables. or semiregular variables; that is, they vary in brightness and appear to pulsate, an indication of these stars' internal instability.

Owing to its low gravityThis article covers the physics of gravitation. See also gravity (disambiguation). Gravitation is the tendency of masses to move toward each other. The first mathematical formulation of the theory of gravitation was made by Sir Isaac Newton and proved ast, as much as half (or more) of the total mass of a carbon star may be lost by way of powerful stellar winds. The star's remnants, carbon-rich "dust" similar to graphiteGraphite is one of the allotropes of carbon. See also allotropes of carbon. Unlike diamond, graphite is a conductor, and can be used, for instance, as the material in the electrodes of an electrical arc lamp. The pi orbital electrons delocalized across th, therefore become part of the interstellar dust. This dust is believed to be a significant factor in providing the raw materials for the creation of subsequent generations of stars. The ablated material surrounding a carbon star may blanket it to the extent that the dust absorbs all visible light.