Gaia and HST astrometry of the very massive $\sim$150 $M_\odot$
  candidate runaway star VFTS682
  How very massive stars form is still an open question in astrophysics.
VFTS682 is among the most massive stars known, with an inferred initial mass of
$\sim$150 $M_\odot$ . It is located in 30 Doradus at a projected distance of 29
pc from the central cluster R136. Its apparent isolation led to two hypotheses:
either it formed in relative isolation or it was ejected dynamically from the
cluster. We investigate the kinematics of VFTS682 as obtained by Gaia and
Hubble Space Telescope astrometry. We derive a projected velocity relative to
the cluster of $38 \pm 17 \mathrm{km \ s^{-1}}$ (1$\sigma$ confidence
interval). Although the error bars are substantial, two independent measures
suggest that VFTS682 is a runaway ejected from the central cluster. This
hypothesis is further supported by a variety of circumstantial clues. The
central cluster is known to harbor other stars more massive than 150 $M_\odot$
of similar spectral type and recent astrometric studies on VFTS16 and VFTS72
provide direct evidence that the cluster can eject some of its most massive
members, in agreement with theoretical predictions. If future data confirm the
runaway nature, this would make VFTS682 the most massive runaway star known to
date.
