A&A 462, 341-344 (2007)
Photometry of 2004 RZ164: a probable binary asteroidT. Kwiatkowski1, A. Kryszczynska1, A. Marciniak1, W. Borczyk1, G. Masi2, A. Galád3, 4, R. Goncalves5, and F. Colas6
1 Astronomical Observatory, Adam Mickiewicz University, Sloneczna 36, 60-286 Poznan, Poland
2 Department of Physics, University of Rome Tor Vergata, via della Ricerca Scientifica 1, 00133 Rome, Italy
3 Modra Observatory, Department of Astronomy, Physics of the Earth, and Meteorology, FMPI, Comenius University, 842 48 Bratislava, Slovakia
4 Astronomical Institute AS CR, 251 65 Ondrejov, Czech Republic
5 Instituto Politecnico de Tomar, Area de Fisica, 2300-313 Tomar, Portugal
6 Institut de Mécanique Céleste, 77 Av. Denfert Rochereau, 75014 Paris, France
(Received 18 April 2006/ Accepted 27 September 2006)
Aims.We observed a near-Earth asteroid 2004 RZ164 to study its rotational properties. The object was chosen because of its small diameter of about 700 m, which is close to the 150 m threshold, separating monolithic and rubble-pile asteroids.
Methods.With small telescopes at five observatories, equipped with CCD cameras, we obtained seven lightcurves, which were taken through the clear, R, and I filters.
Results.Despite significant changes in the observing geometries (and large phase angles during observations), the peak-to-peak amplitudes of the lightcurves never exceeded , suggesting the almost spheroidal shape of this asteroid. There is a signature of a probable occultation/eclipse event in one of the lightcurves, which suggests 2004 RZ164 is a binary asteroid. Its primary component spins with a period of and the orbital period of the system is longer than .
Key words: techniques: photometric -- minor planets, asteroids
© ESO 2007