The size of meteoroid constituent grains: Implications for interstellar meteoroids

The most widely accepted model for the structure of cometary meteoroids is a dustaball with grains bound together by a more volatile substance [1]. In this paper we estimate the size distribution of dustball grains from meteor flare duration, using image intensified CCD or 1998 Leonid meteors. Upon the assumption of simultaneous release of dustball grains at the beginning of the flare, numerical atmospheric ablation models suggest that the dustball grains in these Leonids are of the order of 10−5 to 10−4 kg, which is somewhat larger than estimates obtained by other methods. If the dustball grain sizes determined here are representative of cometary meteoroid structure in general, only the most massive (O and BO) type stars could eject these grains into interstellar space by radiation pressure forces.