The study of runaway candidate stars in the 30 Doradus region: Using Gaia DR2 data

Abstract

We explore the Gaia DR2 relative proper motions of seven young, massive, OB type runaway candidate stars presented by Platais et al. (2018) in the 30 Doradus (30 Dor) region of the Large Magellanic Cloud (LMC). The stars are slow runaways in the tangential plane of the 30 Dor region with relative proper motions μ ≤ 0.4 mas yr^-1 that correspond to a tangential velocity of 100 kms^-1 with respect to their subfields, and they have angular separation from the core of the 30 Dor less than the size of the 30 Dor region. We estimated the flight times of the target stars to the young, massive cluster R136 using angular separation from the cluster and their relative proper motion with respect to the cluster. VFTS 8 and VFTS 65 are inconsistent with even an early ejection from the cluster R136 because the flight time to R136 exceeds their ages significantly. The runaways VFTS 219, VFTS 285, and VFTS 290 could be runaways from R136, as they have flight times to R136 consistent with late ejection from it and have proper motions and positions consistent with the runaway scenario from R136. VFTS 406 and VFTS 838, have direction of motions inconsistent with the R136 runaway scenario, but kinematic ages consistent with late ejection from it.