CCD photometry and new models of 5 minor planets

¹ Department of Experimental Physics & Astronomical Observatory, JATE University, H-6720 Szeged, Dóm tér 9., Hungary
² Guest Observer at Konkoly Observatory, Hungary
³ Department of Physical Geography, ELTE University, H-1088 Budapest, Ludovika tér 2., Hungary

Received: 28 June 1999
Accepted: 6 September 1999

Abstract

We present new R filtered CCD observations of 5 faint and moderately faint asteroids carried out between October, 1998 and January, 1999. The achieved accuracy is between 0.01-0.03 mag, depending mainly on the target brightness. The obtained sinodic periods and amplitudes: 683 Lanzia – , 0.13 mag; 725 Amanda – , ≥0.40 mag; 852 Wladilena – , 0.32 mag (December, 1998) and 0.27 mag (January, 1999); 1627 Ivar – , 0.77 mag (December, 1998) and 0.92 mag (January, 1999). The Near Earth Object 1998 PG unambiguously showed doubly-periodic lightcurve, suggesting the possibility of a relatively fast precession (, ). Collecting all data from the literature, we determined new models for 3 minor planets. The resulting spin vectors and triaxial ellipsoids have been calculated by an amplitude-method. Sidereal periods and senses of rotation were calculated for two asteroids (683 and 1627) by a modified epoch-method. The results are: , , , , = 01964156 ± 00000001, retrograde; , , , ; , , , , = 01999154 ± 00000003, retrograde. The obtained shape of 1627 is in good agreement with radar images by [Ostro et al. (1990)].