Carbon (C) is the element with atomic number 6, symbol C. Its usual Isotope has atomic weight 12, but weight 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.
The Carbon to Oxygen ratio of stars is of interest in identifying systems similar to ours, i.e., planets Earth-like in 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.
Asymptotic Giant Branch (AGB)
Carbonaceous Chondrite (C Chondrite)
Carbon Monoxide (CO)
Carbon Dioxide (CO2)
Millimeter-wave Intensity Mapping Experiment (mmIME)
Neutrons from Carbon-13
Polycyclic Aromatic Hydrocarbon (PAH)
State of Ionization
Tomographic Ionized-Carbon Mapping Experiment (TIME)
Triple Alpha Process