  We report the serendipitous discovery of a peculiar main sequence in archived
Hubble Space Telescope WFPC2 observations of the young star cluster NGC 2011 in
the Large Magellanic Cloud. The bright part of this main sequence exhibits a
prominent double, fork-like feature, as if it consists of twin main sequences,
one of them being redder. The color-magnitude diagram, constructed from the
stars found in the only available WFPC2 field of the cluster, is used to
distinguish the stars according to their membership to each of these sequences
and to study their spatial distribution. We find that there are two well
distinguished populations in the sense that the redder main sequence is
dominated by stars that belong to the main body of the cluster, while the stars
of the bluer main sequence belong to the surrounding region. Providing that NGC
2011 is a verified binary cluster, with the second companion unfortunately not
observed, and taking into account the general region where this cluster is
located, we discuss the possible scenarios from both star formation, and early
dynamical evolution point-of-view that might explain this unique discovery.
