Apparent close approaches between near-Earth asteroids and quasars*
Precise astrometry and frame linking
Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE), Observatoire de Paris, 77 avenue Denfert-Rochereau,
75014 Paris Cedex, France e-mail: [nedelcu;mirel.birlan]@imcce.fr
2 Astronomical Institute of the Romanian Academy, 5 Cuţitul de Argint, 040557 Bucharest, Romania e-mail: [nedelcu;octavian;petre;paras]@aira.astro.ro
3 Observatoire de Paris, Systemes de Referecnce Temps Espace (SYRTE), CNRS/UMR8630 Paris, France e-mail: firstname.lastname@example.org
4 Universidade Federal do Rio de Janeiro, Observatorio do Valongo, Ladeira Pedro Antonio 43, CEP 20.080 – 090 Rio De Janeiro RJ, Brazil e-mail: email@example.com
5 Observatorio Nacional/MCT, R. General Jose Cristino 77, CEP 20921-400 Rio de Janeiro RJ, Brazil e-mail: firstname.lastname@example.org
Accepted: 24 September 2009
Aims. We investigate the link between the International Celestial Reference Frame (ICRF) and the dynamical reference frame realized by the ephemerides of the Solar System bodies.
Methods. We propose a procedure that implies a selection of events for asteroids with accurately determined orbits crossing the CCD field containing selected quasars. Using a Bulirsch-Stoer numerical integrator, we constructed 8-years (2010–2018) ephemerides for a set of 836 numbered near-Earth asteroids (NEAs). We searched for close encounters (within a typical field of view of ground-based telescopes) between our selected set of asteroids and quasars with high-accuracy astrometric positions extracted from the Large Quasars Astrometric Catalog (LQAC).
Results. In the designated period (2010–2018), we found a number of 2924, 14 257, and 6972 close approaches (within 10) between asteroids with a minimum solar elongation value of 60°and quasars from the ICRF-Ext2, the Very Large Baseline Array Calibrator Survey (VLBA-CS), and the Very Large Array (VLA), respectively. This large number of close encounters provides the observational basis needed to investigate the link between the dynamical reference frame and the ICRF.
Key words: methods: statistical / astrometry / reference systems / ephemerides / minor planets, asteroids: general
Table 2 is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (126.96.36.199) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/509/A27
© ESO, 2010