New Evidence for the Dynamical Decay of a Multiple System in the Orion Kleinmann-Low Nebula

Abstract

We have measured astrometry for members of the Orion Nebula Cluster with images obtained in 2015 with the Wide Field Camera 3 on board the Hubble Space Telescope. By comparing those data to previous measurements with NICMOS on Hubble in 1998, we have discovered that a star in the Kleinmann-Low Nebula, source x from Lonsdale et al. (1982), is moving with an unusually high proper motion of 29 mas/yr, which corresponds to 55 km/s at the distance of Orion. Previous radio observations have found that three other stars in the Kleinmann-Low Nebula (BN and sources I and n) have high proper motions (5-14 mas/yr) and were near a single location ~540 years ago, and thus may have been members of a multiple system that dynamically decayed. The proper motion of source x is consistent with ejection from that same location 540 years ago, which provides strong evidence that the dynamical decay did occur and that the runaway star BN originated in the Kleinmann-Low Nebula rather than the nearby Trapezium cluster. However, our constraint on the motion of source n is significantly smaller than the most recent radio measurement, which indicates that it did not participate in the event that ejected the other three stars.

Astrophysical Journal Letters, in press

References in corpus (7)

• The distance to the Orion Nebula
• An Optical Spectroscopic Study of T Tauri Stars. I. Photospheric Properties
• The Gould's Belt Distances Survey (GOBELINS) II. Distances and structure towards the Orion Molecular Clouds
• Monitoring the Large Proper Motions of Radio Sources in the Orion BN/KL Region
• Radio Measurements of the stellar proper motions in the core of the Orion Nebula Cluster
• ALMA Observations of Orion Source I at 350 and 660 GHz
• The Proper Motions of the Double Radio Source n in the Orion BN/KL Region

Cited by in corpus (11)

• Orion Source I's disk is salty
• The Orion Protostellar Explosion and Runaway Stars Revisited: Stellar Masses, Disk Retention, and an Outflow from BN
• A gravitational and dynamical framework of star formation: The Orion Nebula
• The Explosion in Orion-KL as Seen by Mosaicking the Magnetic Field with ALMA
• The complexity of Orion: an ALMA view III. The explosion impact
• HST astrometry in the Orion Nebula Cluster: census of low-mass runaways
• Evidence for dense gas heated by the explosion in Orion KL
• Extremely high excitation SiO lines in disk-outflow system in Orion Source I
• A Massive Young Runaway Star in W49 North
• A molecular-line study of the interstellar bullet engine IRAS 05506+2414
• Formation of Orion Fingers