Old open clusters in the Sagittarius dSph tidal stream -- kith or kin?
  A widely supported formation scenario for the Galactic disc is that it formed
inside-out from material accumulated via accretion events. The Sagittarius
dwarf spheroidal galaxy (Sgr dSph) is the best example of a such accretion, and
its ongoing disruption has resulted in that its stars are being deposited in
the Milky Way halo and outer disc. It is therefore appealing to search for
possible signatures of the Sgr dSph contribution to the build-up of the
Galactic disc. Interestingly, models of the Sgr dSph stream indicate clearly
that the trailing tail passes through the outer Galactic disc, at the same
galactocentric distance as some anti-centre old open star clusters. We
investigate in this Letter the possibility that the two outermost old open
clusters, Berkeley~29 and Saurer~1, could have formed inside the Sgr dSph and
then left behind in the outer Galactic disc as a result of tidal interaction
with the Milky Way. The actual location of these two star clusters, inside the
Sgr dSph trailing tail, is compatible with this scenario, and their chemical
and kinematical properties, together with our present understanding of the
age-metallicity relationship in the Sgr dSph, lends further support to this
possible association. Hence, we find it likely that the old open star clusters
Berkeley~29 and Saurer~1 have extra-galactic origins.
