Fine structure in the inner dust shell of IRC+10216 from lunar occultationobservations at 2.2 mu m

Lunar occultation observations of the inner dust shell surrounding the carb on-rich long-period variable IRC+10216 obtained in the near-infrared K band have yielded a one-dimensional scan across the source (at position angle 3 04 degrees) with a high angular resolution of 1 milliarcsec. Analysis of th e occultation light curve shows significant departures from a spherically s ymmetric uniform disc model, indicating that the dust shell of IRC+10216 is extremely clumpy. Apart from a dominant component A, at least three other components (B, C, D) are seen within the clumpy structure. Comparison with earlier speckle observations confirms that real spatial changes are taking place in the clumpy structure over time-scales of a few years.