The August θ-Aquillid fireballs and possible relationship with the asteroid 2004MB6

Kokhirova, G. I. and Babadzhanov, P. B. (2015)

Meteoritics & Planetary Science. doi: 10.1111/maps.12431


Three bright fireballs belonging to the August θ-Aquillid (ATA) meteor shower were photographed by the Tajikistan fireball network in 2009. Two of them are classified as the meteorite-dropping fireballs according to the determined parameters of the atmospheric trajectories, velocities, masses, and densities. Detection of the more dense bodies among cometary meteoroids points to a heterogeneous composition of the parent comet, and supports the suggestion that some meteorites might originate in the outer solar system, in the given case from the Jupiter-family comet reservoir. A search for the stream’s parent was undertaken among the near-Earth asteroids (NEAs); as a result, the asteroid 2004MB6 was identified as a possible progenitor of the ATA meteoroid stream. Investigation of the orbital evolution of the 2004MB6 and the fireball-producing meteoroid TN170809A showed that both objects have similar secular variations in the orbital elements during 7 kyr. The comet-like orbit of the 2004MB6 and its association with the ATA shower suppose a cometary origin of the asteroid.