* Astronomy

Low-Mass Runaway Stars from the Orion Trapezium Cluster
Authors: Arcadio Poveda, Christine Allen, Alejandro Hernandez-Alcantara

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, researchers have come across several faint OB stars with proper motions larger than one arc second per century.



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 larger or equal than 0.5 (69 km/s), and a proper motion vector which suggests that it was accelerated by the component C of the Trapezium some 1000 years ago. A closer examination of those JW catalogue stars with proper motion larger than one arcsec per century revealed that two other stars, JW 349 and JW 355 (with transverse velocities of 38 and 90 km/s respectively), in spite of being listed with P = 0 by Jones & Walker, should also be considered part of the cluster, because these objects are also externally ionized proplyds.
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.

JW 451 Position(2000): RA: 05 35 14.7 Dec: -05 23 23
JW 355 Position(2000): RA: 05 35 10.8 Dec: -05 22 46
JW 349 Position(2000): RA:05 35 10.5 Dec: -05 24 16

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