The colors are the different radial velocities measured by the radar.
This results in different relative velocities, and "you actually get a pileup of air on one side," he said.
It's also possible that these stars may have had very different velocities and are no longer anywhere near one another in space.
Notice that one frame in free fall can have a very different velocity and acceleration from another such frame.
"Must have come through with different velocities," Blaine said.
Associated with propagation of a disturbance are several different velocities.
An object made of wood might fall at a different velocity than one made of iron.
Even when places move at different velocities, say the poles and equator, the relative effect is minor.
Eventually their slightly different relative velocities will see them scattered throughout the galaxy.
In that way, the influence of different velocities during Earth's orbit around the sun can be observed.