Minor Planets. III. Lightcurves of a Trojan Asteroid

Lightcurves for 624 Hektor were obtained in 1957 with the Radcliffe 188-cm, in 1965 with the Kitt Peak 213cm, in 1967 with the Catalina 154cm, and in 1968 with the Cerro Tololo 152-cm reflectors. The ampli- tudes of the lightcurves were respectively 0.8, 0.1, 0.4, and 1.1 mag. Hektor, therefore, is strongly elongated and its rotational axis is close to the plane of the ecliptic. The shape probably is that of a cylinder with rounded ends, the total length being about 110 km and the diameter 4Q km. The reflectivity and the UB V colors are uniform over the surface. The sense of rotation is direct and the sidereal period is 55"'2 1.115 ( oS.O04 p. e.). The ecliptic longitude and latitude of the North Pole are (for 1950) 324 (+3 and +10 (+2 .