CARBON CYCLE
One of the two main routes whereby hydrogen is converted into helium inside stars.. The carbon cycle is the main source of energy in stars more massive than the Sun.
CARBON STAR ...
Carbon Cycle
A series of nuclear reactions in which carbon is used as a catalyst to transform hydrogen into helium: 12C(p, )13N(p, ) 14O( +)14N(p, )15O( +)15N(p, )12C.
carbon cycle
A nuclear fusion reaction cycle that occurs in the cores of stars with masses greater than that of our Sun, with temperatures exceeding 16 million degrees.
Carbon cycle
Main article: Carbon cycle
Diagram of the carbon cycle. The black numbers indicate how much carbon is stored in various reservoirs, in billions of tons ("GtC" stands for gigatons of carbon; figures are circa 2004).
carbon cycle - (n.)
A chain of nuclear reactions, involving carbon at its intermediate stages, that transforms four hydrogen atoms into one helium atom with a resulting release in energy.
Carbon cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and Earth's atmosphere of the Earth....
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Venus has no carbon cycle to lock carbon back into rocks and surface features, nor does it seem to have any organic life to absorb it in biomass.
carbon cycle (NASA Thesaurus) The path of carbon in living beings in which carbon dioxide is fixed by photosynthesis to form organic nutrients and ultimately restored to the inorganic state by respiration and protoplasmic decay.
A flowchart of the carbon cycle on the Earth is given on the Earth-Venus-Mars page. While the flowcharts for Venus and Mars show what happened long ago, the flowchart for the Earth shows the cycle as it currently operates.
Cold Trap ...
carbon cycle A sequence of atomic nuclear reactions and spontaneous radioactive decay which serves to convert matter into energy in the form of radiation and high-speed particles, ...
Those that are actively fusing hydrogen into helium in the middle, that is, in their cores (either through the proton-proton chain or the carbon cycle), are called "main sequence" stars.
The carbon cycle can take place only if the necessary C and N nuclei are present, and it requires higher temperatures (15-20 million kelvins) and is far more temperature-dependent (E T15) than the proton-proton chain (E T4). The cycle yields 26.
What size stars do the proton-proton cycle and the carbon cycle operate in?
What individuals are credited with discovering the sources of stellar energy?
What are the two chains of reactions that effecthydrogen to helium conversion?
Forests and fires play a significant role in the world's carbon cycle, and thus the phenomenon of global warming.
Other nuclear processes which occur in stars with higher core temperatures are the Carbon cycle and the Carbon-Nitrogen cycle. These cycles use Carbon or Carbon and Nitrogen to mediate the conversion of H into He.
Most geologists do recognize the geologic carbon cycle includes subducted carbon which returns to the surface, with studies showing the carbon does rise in various ways.
Venus has the densest atmosphere of all the terrestrial planets, consisting mostly of carbon dioxide, as it has no carbon cycle to lock carbon back into rocks and surface features, nor organic life to absorb it in biomass.
There are two chains of reactions by which the conversion of hydrogen to helium is effected: the proton-proton cycle and the carbon-nitrogen-oxygen cycle (sometimes referred to simply as the carbon cycle).
However, for a planet to be habitable more conditions are required to be met than simply existing in the habitable zone - it must have an atmosphere and a carbon cycle, ...
Major biogeochemical cycles include the water cycle, carbon cycle, oxygen cycle, nitrogen cycle, phosphorus cycle, sulfur cycle, and calcium cycle.
This is the most important fusion process for main sequence stars with mass less than about 1.5 Msun. More massive stars burn hydrogen mainly by an alternate mechanism known as the Carbon cycle, or Carbon--Nitrogen--Oxygen, CNO cycle.
 See also: Cycle, Temperature, Earth, Energy, Sun
  
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