(December 13, 2017 at 9:41 pm)Jehanne Wrote:(December 13, 2017 at 9:12 pm)Gawdzilla Sama Wrote: Why?
If it formed around its parent star, then it was in an elliptical orbit to begin with. To go from an elliptical orbit (E < 0, negative energy, where K < U, "kinetic energy is less than potential") to a hyperbolic orbit (E > 0, where K > U) would require some interaction within its home system. And, then, it would need to be expelled in such a way as to intersect our Sun in its galactic orbit around the Milky Way at around 250 km/s. Given the "local frame of rest", it seems unusual that any natural object could gain enough energy to, 1) escape its parent star, and 2) to have an intersecting orbit with a neighboring stellar system.
But, "extraordinary claims demand extraordinary evidence" (unless, of course, one is a Christian or Muslim).
P.S. Local standard of rest:
https://en.wikipedia.org/wiki/Local_standard_of_rest
My point was that there's no reason to believe such objects form exclusively around stars.