  The Desert Fireball Network observed a significant outburst of fireballs
belonging to the Southern Taurid Complex of meteor showers between October 27
and November 17, 2015. At the same time, the Cameras for Allsky Meteor
Surveillance project detected a distinct population of smaller meteors
belonging to the irregular IAU shower #628, the s-Taurids. While this returning
outburst was predicted and observed in previous work, the reason for this
stream is not yet understood. 2015 was the first year that the stream was
precisely observed, providing an opportunity to better understand its nature.
We analyse the orbital elements of stream members, and establish a size
frequency distribution from millimetre to metre size range.
  The stream is highly stratified with a large change of entry speed along
Earth's orbit. We confirm that the meteoroids have orbital periods near the 7:2
mean-motion resonance with Jupiter. The mass distribution of this population is
dominated by larger meteoroids, unlike that for the regular Southern Taurid
shower. The distribution index is consistent with a gentle collisional
fragmentation of weak material.
  A population of metre-sized objects is identified from satellite observations
at a rate consistent with a continuation of the size-frequency distribution
established at centimetre size. The observed change of longitude of perihelion
among the s-Taurids points to recent (a few centuries ago) activity from
fragmentation involving surviving asteroid 2015TX24. This supports a model for
the Taurid Complex showers that involves an ongoing fragmentation cascade of
comet 2P/Encke siblings following a breakup some 20,000 years ago.
