The astrometric results of observations of fast-moving NEAs during close approach to the Earth

Abstract

Current investigation is devoted to ongoing follow-up observations of fast-moving near-Earth asteroids (NEAs) carried out with Rotating-drift-scan CCD technique on small-aperture telescopes in China and Ukraine. The observations were obtained during closest approach (CA) to the Earth in order to get more observational points and extend observational arc. It is especially important for newly discovered NEAs when high-precision astrometry is required to determine and improve the orbital elements making them recoverable in next apparitions. The latest astrometric results of NEAs observations, particularly for newly discovered ones, are presented and analyzed in order to refine their orbits and estimate possible recovery in next CA. The comparative analysis of astrometric positions and orbital elements were done regarding to International Astronomical Union Minor Planet Center database and JPL's HORIZONS ephemerides system. The residual differences (O – C) often show high values for newly discovered NEAs during observation date which explained by lack of available observations for reliable calculations of ephemerid positions. The data for such NEAs is presented and orbital calculations are done.