Most nearby stars move relative to the Sun at speeds below about 30 km/s.Suppose you observe a nearby star that is moving much faster than this (say,300 km/s).Which of the following is a likely explanation for its high speed?
A)It is probably a halo star that is currently passing through the disk.
B)It is a very young star,recently formed.
C)It has been pushed to high speed by the shock wave from a nearby supernova.
D)It is a very high mass star.

Question

Quizplus · Accepted Answer

A) Halo stars, which orbit in the halo of the Milky Way, often have highly elliptical orbits that can bring them through the disk at high speeds, unlike the more circular orbits of disk stars. This explains why a star moving at such a high speed relative to the Sun is likely a halo star.

Most Nearby Stars Move Relative to the Sun at Speeds