Final submission 1435611222 Assigned ID: 1386 ----- Attempting Submission 1 (Fri Mar 01 03:24:34 GMT 2013) ----- HST Phase I Proposal 1386 (orion_apt_phase1.apt) successfully submitted. ----- Attempting Submission 2 (Fri Mar 01 08:04:29 GMT 2013) ----- The dynamics of stars in the Orion Nebula Cluster (ONC) hold the clues to the history of this nearby region of massive star formation. We propose to investigate the stellar dynamics in the ONC with unprecedented depth and accuracy by carrying out an astrometric study of the proper motions of stars in this region, including the Trapezium Cluster and stars in and around the Kleinmann-Low Nebula (KL). Numerous images of the ONC have been taken by the HST between 1995 and 2007 at several wavelengths, so we will take advantage of this long time baseline and of the excellent astrometric properties of this rich data set to construct a new database of proper motions. This astrometric database will be used to tie together the radio, infrared and optical reference frames for the ONC, and to decide between dynamical hypotheses that have been offered for the radio and infrared- bright protostellar objects in the KL Nebula, including the Becklin-Neugebauer source, and the well-studied radio sources "I" and "n". We will also use the proper motion database to look for dynamical substructure and mass segregation in the ONC, as well as runaway stars and other repercussions of cataclysmic dynamical events. The proposing team has considerable experience with astrometric studies of massive clusters, as well as with research on the stellar and protostellar content of the Orion and KL Nebulae. RESOLVED STAR FORMATION 12 Small false false 0.0 0.0 false false false SUPPORTED