In 1937, a Soviet physics genius was fearful of being arrested by the secret police. Lev Landau is a legend of physics. But when some of his friends were arrested by Stalin's NKVD and shot, Landau felt he was next. Landau's strategy for stalling his arrest was to...write a paper. He thought that if he could get famous, he would be able to avoid arrest. He selected one of his many brilliant ideas and worked it out. Landau's idea was that stars possess a neutron core. It was quite similar to the neutron star idea already proposed by Swiss astronomer Fritz Zwicky some years earlier. A neutron star is a celestial object formed almost entirely of neutrons. Neutrons are one of the three components of the atom, but unlike protons or electrons they do not have electrical charge. Also, it is possible for protons and electrons to fuse and form a neutron (and vice versa). As we now know, when stars run out of the nuclear fuel that keeps them burning, they start shrinking under their own gravity. As they get denser and hotter, the conditions are ripe for protons and electrons to fuse and form neutrons. The upshot is stars transforming into a superdense, neutron-rich object. When heavy stars die, this is what they become. Landau's idea was that ordinary stars have at their core a neutron star which helps fuel them. This was suggested as an alternative to the idea that stars draw their fuel from nuclear reactions, an idea which still had not been worked out in detail at the time. Neutron stars, being very dense, can pack a lot of punch gravitationally. A neutron core can accelerate an atom to very high speeds. This kinetic energy converted into heat could fuel a star, Landau showed. Landau thought stars like the Sun could have a neutron core, but it was soon proved to be wrong. At present we do not know any celestial objects that do have neutron cores. But his work helped draw physicists like Oppenheimer into the field, who made important contributions. Landau's paper was published in Nature and made a big splash. Soviet newspapers celebrated his scientific breakthrough. But it was not enough to prevent the NKVD from knocking on his door. The picture below is his mug shot from his arrest. For the story of Landau's arrest, read the wonderful thread by @VergaraLautaro linked below (the mug shot of Landau is also taken from there)