Astrophysics (index)about


(element, C, atomic number 6)

Carbon (C) is the element with atomic number 6, symbol C. Its usual isotope has mass number 12, but mass number 13 is stable and 14 has a 5730 year half-life. It is the fourth most common element. The Milky Way is about 0.5% carbon by mass.

It results from the CNO cycle and the triple alpha process.

The carbon to oxygen ratio of stars is of interest in identifying systems similar to ours, i.e., planets with Earth-like composition.

The carbon forbidden lines [CII] (e.g., 1900GHz, 158um) of singly-ionized carbon (CII, i.e., C+) and [CI] (e.g., 492GHz) of neutral carbon (CI) are seen in cooling clouds, being the result of fine structure atomic excitation from collisions, and escaping clouds easily, effectively turning thermal kinetic energy into escaping electromagnetic radiation. Thus they used along with carbon monoxide spectral lines to locate molecular clouds. The former maps to a microwave atmospheric window at high redshifts, thus has been proposed for mapping the high-redshift universe.


Referenced by:
asymptotic giant branch (AGB)
alpha process
carbonate-silicate cycle
carbonate system
carbon planet
carbon star
carbonaceous chondrite (C chondrite)
methylidyne (CH)
methane (CH4)
ionized carbon fine structure line ([CII])
carbon monoxide (CO)
carbon dioxide (CO2)
cosmic dust
dalton (Da)
diffuse interstellar bands (DIBs)
ethylene (C2H4)
fine structure
horizontal branch (HB)
acetylene (C2H2)
hydrocarbon (HC)
ice giant
metallicity (Z)
Millimeter-wave Intensity Mapping Experiment (mmIME)
neutron scattering
neutrons from carbon-13
nitrogen (N)
polycyclic aromatic hydrocarbon (PAH)
PAH emissions
post main sequence star
radioactive dating
red clump (RC)
sodium (Na)
state of ionization
S-type star
Tomographic Ionized-carbon Mapping Experiment (TIME)
triple alpha process
white dwarf