Radio continuum monitoring of the extreme carbon star IRC+10216
  We describe Very Large Array observations of the extreme carbon star IRC+10216 at 8.4, 14.9, and 22.5 GHz made over a two year period. We find possible variability correlated with the infrared phase and a cm- to sub-millimeter wavelength spectral index very close to 2. The variability, observed flux densities, and upper limit on the size are consistent with the emission arising from the stellar photosphere or a slightly larger radio photosphere. 
K. M. Menten (1), M. J. Reid (2), E. Kruegel (1), M. J. Claussen (3),   R. Sahai (4) ((1) MPIfR, (2) CfA, (3) NRAO, (4) JPL)