All Figures

$\begin{figure} \par\resizebox{5cm}{!}{\rotatebox{0}{\includegraphics{3790F1.ps}}} \end{figure}$ Figure 1: Two consecutive interferograms of R CrB. The fringes are spectrally dispersed in the horizontal direction and are recorded simultaneously in the J, H, and $K^{\prime }$ bands, as shown in each panel. These three bands are separated by telluric absorption, which can be seen as vertical dark lanes between the J and H bands as well as between the H and $K^{\prime }$ bands.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\rotatebox{0}{\includegraphics[bb=26 417... ...{\rotatebox{0}{\includegraphics[bb=26 28 544 350,clip]{3790F2.ps}}} \end{figure}$ Figure 2: Comparison of the observed SED and visibilities with SEDs and visibilities predicted by two-component models consisting of the central star and an optically thin dust shell, as described in Sect. 4.1. a) The filled circles represent the photometric data obtained five days after the IOTA observations. The filled triangles represent IRAS data. The three curves represent models with different opacities for amorphous carbon. RM: Rouleau & Martin (1991), CO: Colangeli et al. (1995), BU: Bussoletti et al. (1987). $T_{\rm in}$ is the temperature at the inner boundary ( $r_{\rm in}$ ) of the optically thin dust shell. $\tau _{V}$ is the optical depth of a dust shell defined at 0.55 $\mu$ m. b) The filled diamonds represent the J-, H-, and $K^{\prime }$ -band visibilities observed with IOTA. The filled circles represent the $K^{\prime }$ -band visibility obtained by speckle interferometry with the 6 m telescope at the Special Astrophysical Observatory, Russia (Paper I). For each of the RM, CO, and BU models, the predicted visibilities in the J, H, and $K^{\prime }$ bands are shown.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\rotatebox{0}{\includegraphics{3790F3.ps}}}\end{figure}$ Figure 3: An example of the intensity distribution of a model with a group of dust clouds, which are randomly distributed at distances of between 2 $R_{\star }$ and 20 $R_{\star }$ in the plane of the sky. The intensity is represented in a logarithmic grayscale, where the brighter gray corresponds to the higher intensity. The five intensity peaks located near the central star ( $\times$ ) correspond to newly formed dust clouds. The ring-shaped intensity distribution results from limb brightening of the inner boundary of the optically thin dust shell at 78 $R_{\star }$ (18 mas). The projected baseline used in the calculation of the visibilities is shown by the solid line.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\rotatebox{0}{\includegraphics[bb=27 417... ...{\rotatebox{0}{\includegraphics[bb=26 27 543 347,clip]{3790F4.ps}}} \end{figure}$ Figure 4: Comparison of the observed SED and visibilities with SEDs and visibilities predicted by models consisting of the central star, an optically thin dust shell, and a group of five newly formed dust clouds, as shown in Fig. 3. The dashed-dotted line in a) represents the contribution of the group of newly formed dust clouds in the RM model. See also the legend to Fig. 2.
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In the text

$\begin{figure} \par\resizebox{5cm}{!}{\rotatebox{0}{\includegraphics{3790F1.ps}}} \end{figure}$	Figure 1: Two consecutive interferograms of R CrB. The fringes are spectrally dispersed in the horizontal direction and are recorded simultaneously in the J, H, and $K^{\prime }$ bands, as shown in each panel. These three bands are separated by telluric absorption, which can be seen as vertical dark lanes between the J and H bands as well as between the H and $K^{\prime }$ bands.
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$\begin{figure} \par\resizebox{8.8cm}{!}{\rotatebox{0}{\includegraphics[bb=27 417... ...{\rotatebox{0}{\includegraphics[bb=26 27 543 347,clip]{3790F4.ps}}} \end{figure}$	Figure 4: Comparison of the observed SED and visibilities with SEDs and visibilities predicted by models consisting of the central star, an optically thin dust shell, and a group of five newly formed dust clouds, as shown in Fig. 3. The dashed-dotted line in a) represents the contribution of the group of newly formed dust clouds in the RM model. See also the legend to Fig. 2.
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