EVOLUTION OF DUST TRAILS INTO BANDS

We use numerical simulations to investigate the production of dust trails by asteroid disruption events. Our work shows that asteroid trails evolve into pairs of dust bands over time. Coherent trails typically survive several tens of kyr before evolving into complete bands after1Myr. The transition timescale depends sensitively on the location of the source breakup event in the main asteroid belt. Bands develop more efficiently from sources in the middle/outer belt than in the inner belt, which may not produce observable pairs of bands at all. The infrared structures produced by recent disruption events (<1Myr) are characterized by a complicated and changing set of incomplete arcs and cusps. Their geometry depends both on the observer’s position and on the source’s location in terms of heliocentric distance and inclination to the ecliptic. We postulate that the broad orphan trails named C and D by Sykes in 1988 might have been produced by the formation of the Datura asteroid family 450 50 kyr ago. Additional work will be needed to test this link. Subject headinggs: celestial mechanics — infrared: solar system — interplanetary medium Online material: color figure 1