In the course of a search for common proper motion binaries in the Jones & Walker ( JW ) catalogue of proper motions in the Orion Nebula Cluster , we came across several faint stars with proper motions larger than one arcsecond per century and probabilities of membership P larger than 0.90 .
Such stars are interesting because they could be low-mass runaway stars recently accelerated by n -body interactions in compact multiple systems .
Of particular interest among these stars is JW 451 , which has a P = 0.98 , the largest transverse velocity among all the stars with P \geq 0.5 ( 69 \pm 38 km s ^ { -1 } ) , and a proper motion vector which suggests that it was accelerated by the \theta ^ { 1 } Orionis C triple system some 1000 years ago .
A closer examination of those JW stars with \mu > 1 \arcsec century ^ { -1 } revealed that two other stars , JW 349 and JW 355 ( with transverse velocities of 38 \pm 9 and 90 \pm 9 km s ^ { -1 } respectively ) , in spite of being listed with P = 0 by JW , should also be considered part of the cluster , because these objects are also externally ionized proplyds .
In fact , Hillenbrand ( 1997 ) assigns to them probabilities of membership of 0.99 .
Moreover , the proper motion errors of these two stars are relatively small , and so they are good candidates to be runaway stars recently accelerated in the Orion Nebula Cluster .