Orbital structure of a meteoric complex in a vicinity of the Earth's orbit by Kazan meteor radar. Types of meteor orbits

Abstract

© 2018 Elsevier Ltd The orbital structure of a meteoric complex in a vicinity of the Earth's orbit is substantially defined by conditions of its observation from the Earth. Orientation of aerials of Kazan meteor radar varied each 15 min to the North, East, South and West – the directions to provide the maximal review of northern celestial hemisphere together with the Earth's rotation. Nevertheless, the antiapex area of celestial sphere was practically inaccessible due to influence of the physical factor of small radar sensitivity to meteors with velocities less than 18 km/s. On the contrary, the meteor streams in which movements are backward compared to the Earth's movement, are quite observationally accessible. In the given work, the data of meteor radar observation from August to November of 1986 are resulted. The conditions of observation have defined some types of orbits: internal orbits with aphelion distance Q∼1 AU and with a wide spectrum of perihelion distances and external orbits with perihelion distance q∼1 AU and with a wide spectrum of aphelion distances. The majority of all observed orbits are close to circular orbits for which Q∼1 AU and q∼1 AU. Three-dimensional maps of meteor microstream distribution and numbers of meteors in them by perihelion, by aphelion distances and by inclinations are constructed. Orbital parameters of the most significant meteor streams that have been found out are presented.