The importance of molecular Rayleigh scattering in the atmospheres of very late-type stars

The importance of Rayleigh scattering by various molecules, atoms and ions at low temperatures has been examined for three hydrogen deficient elemental compositions. The major contributors to the Rayleigh scattering have been found to be C3 and N2, though many other molecules, atoms and ions contribute not insignificantly. A comparison between the Rayleigh scattering by C3 and N2 with absorption by negative ions and electron scattering suggests that the Rayleigh scattering by these molecules may be important in the atmospheres of cool hydrogen deficient giant and supergiant stars