Runaway Young Stars in the Orion Nebula
  The star forming region of the Orion Nebula (ONC) is ideal to study the
stellar dynamics of young stars in a clustered environment. Using Gaia DR2 we
search for the pre-main sequence stars with unusually high proper motions that
may be representative of a dynamical ejection from unstable young triple
systems or other close three-body encounters. We identify twenty-six candidate
stars that are likely to have had such an encounter in the last 1 Myr. Nine of
these stars could be traced back to the densest central-most region of the ONC,
the Trapezium, while five others have likely interactions with other OB-type
stars in the cluster. Seven stars originate from other nearby populations
within the Orion Complex that coincidentally scattered towards the ONC. A
definitive point of origin cannot be identified for the remaining sources.
These observations shed light on the frequency of the ejection events in young
clusters.
