Enhanced activity of the Southern Taurids in 2005 and 2015

In this paper, we present an analysis of Polish Fireball Network (PFN) observations of enhanced activity of the Southern Taurid meteor shower in 2005 and 2015. In 2005, between October 20 and November 10, seven stations of the PFN determined 107 accurate orbits, with 37 of them belonging to the Southern Taurid shower. In the same period of 2015, 25 stations of the PFN recorded 719 accurate orbits with 215 orbits of the Southern Taurids. Both maxima were rich in fireballs, which accounted for 17 per cent of all observed Taurids. The whole sample of Taurid fireballs is uniform in the sense of starting and terminal heights of the trajectory. However, a clear decreasing trend in geocentric velocity with increasing solar longitude was observed. The orbital parameters of observed Southern Taurids were compared to orbital elements of near-Earth objects (NEOs) from the NEODyS-2 data base. Using the Drummond criterion D with a threshold as low as 0.06, we found over 100 fireballs strikingly similar to the orbit of asteroid 2015 TX24. Several dozens of Southern Taurids have orbits similar to three other asteroids: 2005 TF50, 2005 UR and 2010 TU149. All mentioned NEOs have orbital periods very close to the 7 : 2 resonance with Jupiter's orbit. This confirms the theory of a resonant meteoroid swarm within the Taurid complex, which predicts that, in specific years, the Earth is hit by a greater number of meteoroids capable of producing fireballs.