Astrophysicists obtained for the first time spectra of radiating cobalt registered at the supernova SN2014J, shown above, located 11 million light-years from Earth. Isotope 56Co has a half-life of just 77 days, and does not exist in normal conditions. However, during a giant thermonuclear explosion of a supernova, this short-lived radioactive isotope is produced in large quantities. The reason was the rarity of explosions at such a distance – 11 million light-years is a large value on the galactic scale (the diameter of a galaxy is about 100,000 light-years, the distance between stars is a few light-years), but on an intergalactic scale it is a relatively short distance. There are several hundreds of galaxies within a radius of ten million light-years; supernovae produce explosions like this (type Ia explosions) once every few centuries in a galaxy, including a type Ia supernova that exploded in the Milky Way in 1606.