76mas speckle-masking interferometry of IRC+10216 with the SAO 6m telescope

G. Weigelt, Y. Balega, T. Blöcker, A.J. Fleischer, R. Osterbart and J.M. Winters

Astronomy & Astrophysics, 333, L51-L54 (1998)

Gzipped PostScript version (186 kB)

Abstract:

We present the first K"-band image of the carbon star IRC+10216 with 76mas resolution. The diffraction-limited image was reconstructed from 6m telescope speckle data using the speckle masking bispectrum method. The image shows that the dust shell of IRC+10216 is extremely clumpy. Five individual clouds within a 0".21 radius of the central star have been resolved for the first time.

On the basis of consistent theoretical models we argue that these structures are produced by circumstellar dust formation and suggest specific future observations to test this hypothesis. The fragmentation of the multiple-shell structure gives most likely direct evidence for an inhomogeneous mass-loss process which may be interpreted in terms of large-scale surface convection-cells (Schwarzschild 1975) being a common phenomenon for Red Giants.