Only if the radial velocity alone is greater than the galactic escape velocity at that star's location (assuming we know the distance... another thing that was hard to figure before Hipparcos and Gaia). Consider the worst case, where the radial motion is zero, but the star is a runaway. Unless we can measure its proper motion, we would never know.And is just the radial velocity enough to determine whether a star is a run-away?
It is only recently that we have been able to measure the proper motion for more than a handful of nearby stars. Before Hipparcos and Gaia we simply didn't have the sensitivity to see that motion for most stars. So all we had to work with in most cases was the radial velocity, which is trivially determined spectroscopically from Doppler shift.
Statistics: Posted by johnnydeep — Fri Jan 05, 2024 4:55 pm — Replies 22 — Views 9089