“…This new type of structure (developed for example by ALCATEL SPACE, cf. Bailly et al, 1997) allows to reduce the thermal regulation to half a degree for a relative change of the diameter < 1 mas (1 thousand of a pixel). The isotropic property of carbon-carbon and a detailed knowledge of the experiment (interferometric calibration), will help to further gain, by modeling, a factor 100 to 1000 on the short term diameter variations (useful for the solar limb oscillations).…”