S. Lacour, G. Perrin, X. Haubois, S. Meimon, J. Woillez , P. A. Schuller, and S. T. Ridgway
IMAGING MIRA STARS (Poster)

IMAGING MIRA STARS

S. Lacour(1), G. Perrin(1), X. Haubois(1), S. Meimon(2), J. Woillez (3), P. A. Schuller(4), and S. T. Ridgway(5)
(1) Observatoire de Paris Meudon, France
(2) Office National d'Études et de Recherches Aérospatiales, France
(3) Keck Observatory, USA
(4) Harvard-Smithsonian Center for Astrophysics, USA
(5) National Aeronautics and Space Administration, USA

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 $\sim$ 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.