Interstellar meteoroids in the Japanese tv catalogue

Abstract

The present work is based on an analysis of the 14763 precise determined meteor orbits collected in the Japanese tv catalogue (SonotaCo 2009), with the aim of determining the real proportion of interstellar meteors in this database. If interstellar meteors are present among the registered meteor orbits, the distribution of the excesses of their heliocentric velocities should correspond to the distribution of the radial velocities of close stars. For the velocity vi = 20 kms-1 of an interstellar meteor, with respect to the Sun, we obtain a heliocentric velocity of vH = 46.6 kms -1 of an interstellar meteor arriving at Earth. Any error in the determination of vH, especially near the parabolic limit, can create an artificial hyperbolic orbit that does not really exist. The analysis of the data did not produce any convincing arguments in favour of the existence of true hyperbolic meteors in the catalogue. It was shown that the vast majority of the 484 hyperbolic orbits has been caused by an overestimation of their velocity, and approximately 50% of them belong to meteor showers. Furthermore, the hyperbolic excesses of the velocities in all cases are very low, about one order less than the velocity distribution of neighbouring stars suggest. The upper limit of the proportion of possible interstellar meteors to interplanetary ones among all investigated meteor orbits in the database is 1.3 × 10 -3. © 2011. Astronomical Society of Japan.