The Galactic Environments of Cool Stars - part I: Modeling Interstellar Dust around the Sun and Nearby Cool Stars

Abstract

We present a model of the interaction of interstellar dust grains with a stellar environment, that predicts the distribution of interstellar dust grains in the size range between $0.1 {\rm μm}$ and $1 {\rm μm}$ around a star for the whole stellar cycle. Comparisons of the model results with in-situ dust measurements by the Ulysses spacecraft in the Solar System validate the model. We show that in the case of the Sun, interstellar dust grains can produce large regions of infrared emission that can be confused with a circumsolar dust disk when observed from afar. Our model can determine the shape of interstellar dust concentrations close to nearby stars, if we have information on the relative velocty of the stars with respect to the surrounding interstellar medium, and the properties of the stellar wind.