  The presence of young stellar populations in the Large Magellanic Cloud
cluster NGC 1783 has caught significant attention, with suggestions ranging
from it being a genuine secondary stellar generation to a population of blue
straggler stars or simply contamination from background stars. Thanks to
multi-epoch observations with the Hubble Space Telescope, proper motions for
stars within the field of NGC 1783 have been derived, thus allowing accurate
cluster membership determination. Here, we report that the younger stars within
NGC 1783 indeed belong to the cluster, and their spatial distribution is more
extended compared to the bulk of the older stellar population, consistent with
previous studies. Through N-body simulations, we demonstrate that the observed
characteristics of the younger stars cannot be explained solely by blue
straggler stars in the context of the isolated dynamical evolution of NGC 1783.
Instead, accretion of the external, low-mass stellar system can better account
for both the inverse spatial concentration and the radial velocity isotropy of
the younger stars. We propose that NGC 1783 may have accreted external stars
from low-mass stellar systems, resulting in a mixture of external younger stars
and blue straggler stars from the older bulk population, thereby accounting for
the characteristics of the younger sequence.
