Wolfgang Beisker
München, Germany

Recently, the observation of occultations by Titania and by Tercidina has focussed attention not only on the physical properties of the occultating bodies but also on the dimensions of the star. Since a long time, a lot of work has been done on determing stellar diameters by observing diffraction patterns on the lunar limb, a technology which has been used in many case by the McDonald observatory in Texas. But in case of the moon, high speed data recording is necessary, because only for a few milliseconds the stellar disk can be evaluted by diffraction.
Determing stellar diameters by using occultation by asteroids and other atmosphereless bodies of our solar system is another important technology. Digital imaging, using the Iota Occultation Camera (IOC), standard video equipment or cheap consumer webcam systems allow an easy determination in this case. Up to 60 images per second can be recorded with sufficient digital reolution.
In this report, the limitiations of the technique are discussed as well as practical examples from occultations are presented. Stellar diameters of stars much fainter as for lunar occultations can be determined.
 
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