  We present the first speckle interferometric observations of R CrB, the
prototype of a class of peculiar stars which undergo irregular declines in
their visible light curves. The observations were carried out with the 6m
telescope at the Special Astrophysical Observatory near maximum light (V=7,
1996 Oct. 1) and at minimum light (V=10.61, 1999 Sep. 28). A spatial resolution
of 75mas was achieved in the K-band. The dust shell around R CrB is partially
resolved, and the visibility is approximately 0.8 at a spatial frequency of 10
cycles/arcsec. The two-dimensional power spectra obtained at both epochs do not
show any significant deviation from circular symmetry. The visibility function
and spectral energy distribution obtained near maximum light can be
simultaneously fitted with a model consisting of the central star and an
optically thin dust shell with density proportional to r^-2. The inner boundary
of the shell is found to be 82Rstar (19mas) with a temperature of 920K.
However, this simple model fails to simultaneously reproduce the visibility and
spectral energy distribution obtained at minimum light. We show that this
discrepancy can be attributed to thermal emission from a newly formed dust
cloud.
