In this very sped-up artist's impression showing a collection of distant galaxies, the occasional supernova can be seen. Each of these exploding stars briefly rivals the brightness of its host galaxy. One class of supernovae, Type Ia, which results from thermonuclear runaway explosions on white dwarf stars in binary systems, has been used to map out the expansion rate of the Universe. This work led to the discovery of the accelerating expansion of the Universe and was awarded with the 2011 Nobel Prize for Physics.