Since 2008, Bob Stephens has worked a program of obtaining lightcurves of Trojan Asteroids in order to determine their rotational periods. This family of asteroids shares the orbit Jupiter around the Sun, lying in regions of gravitational stability called the Lagrangian points. These places are ahead of an behind Jupiter by 60 degrees in its orbit. Trojans have been understudied because they are dim and difficult to observe.
Over 4,000 Jupiter Trojan asteroids have been discovered and are divided into two 'camps', the Trojans and the Greeks. It is believed there are more than a million Trojans larger than 1 km in diameter.
To date, only about 80 Trojans have had their rotational periods determined. A couple dozen of those were found by observers at CS3. This is a statistically small number, but is already showing differences from the Main Belt population. There are competing theories about how the Trojans were trapped in their positions, both giving clues to the formation and evolution of the solar system.
