Can S5-HVS1 Retain Its Planets?

[DavidCummings]

TL;DR Summary

If S5-HVS1 ever had planets, would they all get stripped off when the star was ejected from the galaxy?

"Astronomers have spotted an ultrafast star [S5-HVS1], traveling at a blistering 6 million km/h, that was ejected by the supermassive black hole at the heart at the Milky Way five million years ago." -- https://www.sciencedaily.com/releases/2019/11/191112110238.htm

If this star had planets 5 million years ago, when it began its "blistering" journey, could it have held on to any of those planets, or would they all have been stripped off at the time of ejection?

Thanks.

 

[phinds]

Gravitational slingshots produce fairly precise trajectories based on the gravity of the body doing the slingshotting and the closeness of the passby. NASA has made very precise use of this fact. Given the rather extreme results of this apparent event, I would think it likely that the planets would have had enough of a different distance to result is a slightly different trajectory that would likely have caused them to diverge, subsequently, from their sun.

 

[Vanadium 50]

I disagree with phinds. It's going fast, but not crazy fast: about 7x faster than the sun. The star making the closest approach to Sag A* is called S2, traveling 3x faster than that. Just ballparking it, that means a closest approach of around 7 light days and an acceleration of 1.5 x 10^-2 m/s². An earth-like orbit is at 8 light minutes, so the differential acceleration is ~10^-5 m/s². This is much smaller than the actual acceleration of 6 x 10^-3 m/s².

You're probably OK up to the orbit of Saturn or so.