Hektor

Asteroid 624, the largest of the Trojan asteroids, discovered by A. Kopff in 1907. Its brightness varies by a factor of three as it rotates in a period of just under 7 hours. Measurements of the variation indicate that Hektor is cylindrical in shape, 150 km wide by 300 km long. It has been suggested that Hektor may in fact be two asteroids in contact or a close binary.