Star shock wave. Infrared image of a giant shock wave (red arc) created by a speeding star known as Kappa Cassiopeiae. Kappa Cassiopeiae is a B-type supergiant that lies around 4000 light years from Earth, in the constellation Cassiopeia. It is a runaway star, moving at a speed of around 2.5 million miles an hour. Its magnetic field creates this visible bow shock 4 light years ahead of it as its wind of particles collides with interstellar gas and dust. Imaged by NASA's Spitzer Space Telescope.