hektor is one of the most stretched bodies of its size in the solar system, being 370 × 200 km. it is thought that hektor might be a contact binary (two asteroids joined by gravitational attraction) like 216 kleopatra. hubble space telescope sightings of hektor in 1993 did not show an obvious stretched shape because of a limited angular resolution. on july 17, 2006, the keck-10m ii telescope and its laser guide star adaptive optics (ao) system indicated a stretched shape for hektor. additionally, since this ao system provides an excellent and stable correction (angular resolution of 0.060 arcsec in k band), a 15-km moon at 1000 km from hektor was found. the moon's provisional designation is s/2006 (624) 1. hektor is, so far, the only known binary trojan asteroid in the l4 point and the first trojan with a moon. 617 patroclus, another big trojan asteroid in the l5, is made of two same-sized asteroids.