Swan band

Swan bands are a characteristic of the spectra of carbon stars, comets and of burning hydrocarbon fuels.^[1][2] They are named for the Scottish physicist William Swan, who first studied the spectral analysis of radical diatomic carbon (C₂) in 1856.^[3]

Spectrum of the blue flame from a butane torch showing excited molecular radical band emission and Swan bands.

Swan bands consist of several sequences of vibrational bands scattered throughout the visible spectrum.^[4]

See also

• Spectroscopy