Hypervelocity stars have become a hot subject now researchers from Vanderbilt Univ in a collaboration with NASA and ESO have found a new class of these fast moving stars.
These are not blue and luminous, neither do they come from the galactic center, but are more regular sun like stars that move in quite surprising directions. What originally boosted the stars to this velocity and where they originated is still unknown.

Vanderbilt webpage published Thursday Jan 9

I am unconvinced by that paper, as indeed are the authors; I think the graph showing transverse velocities all much higher than radial velocities is damning.

Those transverse velocities come from proper motions on a survey not really optimised for astrometry, combined with photometric distances. I think it would be best to wait for Gaia confirmation.

You might very well be right, also I find this to be extraordinary verging on the unbelievable. Yet their measurement and methodology have stood up to he peer reviewers since it got published in the Astrophysical Journal. So I do find it interesting enough to mention here, even though this forum mainly is for discussion on spacecrafts and rovers.