An unexpected detection of bifurcated blue straggler sequences in the
  young globular cluster NGC 2173
  Bifurcated patterns of blue straggler stars in their color--magnitude
diagrams have atracted significant attention. This type of special (but rare)
pattern of two distinct blue straggler sequences is commonly interpreted as
evidence of cluster core-collapse-driven stellar collisions as an efficient
formation mechanism. Here, we report the detection of a bifurcated blue
straggler distribution in a young Large MagellanicCloud cluster, NGC 2173.
Because of the cluster's low central stellar number density and its young age,
dynamical analysis shows that stellar collisions alone cannot explain the
observed blue straggler stars. Therefore, binary evolution is instead the most
viable explanation of the origin of these blue straggler stars. However, the
reason why binary evolution would render the color--magnitude distribution of
blue straggler stars bifurcated remains unclear.
