Interferometric data of Mira type stars in the near-infrared have
already produce radial visibility curves with a shape far from the
simple limb darkening profile. The measured visibilities as a function
of wavelength revealed the presence in K band of a close ( at a
1 stellar radius distance above the photosphere ) molecular layer.
However, thanks to the phase closure and telescope mobility of the IOTA interferometer, we have now access to the two dimensional complex
visibility profile. We will present the u-v plane of two Mira stars
(including Mira), and we will discuss the problems and advantages of
analyzing complex objects either in the Fourier domain or in the
reconstructed image.
The following figure shows the u-v coverage and
the reconstructed image of Mira. These H band data required ten nights
of observation at the IOTA interferometer in October 2005.