On the nondetection of extrasolar comets

Abstract

This paper reports on calculations of the expected rate for the discovery of comets with significantly hyperbolic orbits, including corrections for the observability of these comets. Using current standard models for the formation of comets, a significant number of such comets should have been observed. This lack of detection of extrasolar comets is becoming an embarassment to the theories of solar system and cometary formation and may drive the parameters of these models.