White dwarf star waves. Image 3 of 3. Computer model of kilometre-high waves on the surface of a white dwarf star, a small, dense star formed at the end of a Sun-like star's life. The arrows show the direction and strength of the wind causing the waves. The largest arrows show winds of up to 2000 kilometres per second. The wind comprises hydrogen drawn to the dwarf from an unseen companion star. Such binary systems are called recurrent novae. Hydrogen builds up on the dwarf's surface, and explodes periodically. Turbulent waves explain why dwarf material is seen in the explosions. This is 0. 055 seconds after the wind started. See images R670/139-141 for a sequence of wave development.