Astron. Astrophys. Suppl. Ser. 137, 363-368

CCD observations of 11 faint asteroids

K. Sárneczky¹³ - Gy. Szabó²³ - L.L. Kiss²³

Send offprint request: l.kiss@physx.u-szeged.hu

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

Received December 8, 1998; accepted April 12, 1999

Abstract:

We present new CCD observations of 11 poorly studied, faint and moderately faint asteroids. Six of them (1089, 1452, 2415, 9262, 1998 FM5, 1989 UR) have never previously been observed photometrically, thus our lightcurves are the first ones in the literature. The achieved accuracy ranges between 0.01-0.03 mag depending mainly on the brightness of the target objects. The obtained sinodic periods and amplitudes: $1089\ -\gt 4\hbox{$.\!\!^{\rm h}$}$, 0.025 mag; $1452\ -17\hbox{$.\!\!^{\rm h}$}2~\pm~0\hbox{$.\!\!^{\rm h}$}1$, $\geq$0.34 mag; $2415\ -\gt 2\hbox{$.\!\!^{\rm h}$}5$, 0.15 mag; $9262\ -\gt 6\hbox{$.\!\!^{\rm h}$}3$, $\geq$0.08 mag; 1989 UR $-\gt 4^{\rm h}$, $\geq$0.15 mag; 1998 FM5 $-\gt 2\hbox{$.\!\!^{\rm h}$}8$, $\geq$0.61 mag.

Additionally, lightcurves are presented for asteroids observed earlier in only one or two oppositions (792, 1508, 1604, 1865). The resulting periods and amplitudes: $792 -9\hbox{$.\!\!^{\rm h}$}19~\pm~0\hbox{$.\!\!^{\rm h}$}01$, $0.76~\pm~0.02$ mag; $1508 -9\hbox{$.\!\!^{\rm h}$}15~\pm~0\hbox{$.\!\!^{\rm h}$}03$,$0.52~\pm~0.01$ mag; $1604 -6\hbox{$.\!\!^{\rm h}$}15~\pm~0\hbox{$.\!\!^{\rm h}$}02$, $\geq0.17~\pm~0.01$ mag; $1865 -6\hbox{$.\!\!^{\rm h}$}87~\pm~0\hbox{$.\!\!^{\rm h}$}03$, $2.3~\pm~0.1$ mag. We have conducted shape fitting with a triaxial ellipsoid and determined spin vector and sens of rotation for 1727 combining our new observations with previously published lightcurves. The results are: $\lambda_{\rm p}=126/306~\pm~10^\circ$,$\beta_{\rm p}=56~\pm~15^\circ$, $a/b=1.9~\pm~0.1$, $b/c=1.6~\pm~0.1$.

Key words: minor planets, asteroids