A library of stellar light variations due to extra-solar comets

We present an extensive study of stellar occultations by extra-solar cometa ry tails through a large number of numerical simulations. The output of the simulations are the star light extinction and scattering as a function of time at. three wavelengths (400; 800 and 2200 nm). We explore the light cur ves dependence over a large set of possible parameters (dust size distribut ions? stellar types, production rates, orbital configurations). This grid o f models, which is electronically available at http://www.iap.fr/users/leca veli/grid will be useful to develop and to test the detection methods? and to analyze the results of the forthcoming high accuracy photometric surveys . With this tool, we quantify the proportion of light curves which could mimi c a planetary occultation. We find that at a signal to noise ratio of 10, a bout 5% of cometary occultation light curves are symmetric enough to be mis taken for a planetary occultation. The total number of planet mimicing come tary occultations could be of the same order as the number of planet occult ations.