On our planet, noble metals like gold and silver prefer to be together. For a long time it was thought that they were friends in the space as both these elements are produced by the same star. However, the work of German astrophysicist Camilla Hansen has shown that it is not the case. Silver appears at the explosion of one type of stars, and gold – very different ones.
According to the most widely available theory of the appearance of heavy metals in the universe, these elements are born in the depths of celestial bodies. The calculations show that due to extreme pressure and temperature, nuclear fusion reaction starts inside these stars. It begins with an elementary transformation of hydrogen nuclei into helium, but then more interesting things start in the massive stars.
Under the intense forces of gravity, temperature and pressure, simple elements converge inside the star core with alpha particles running around free (as well as protons and neutrons (their source is the reaction of the compound nuclei of isotopes 12C to form in one case 23Na, and in another – 23Mg). At one point they even begin to connect with each other in spite of the electrostatic repulsion of like-charged charges. As a result, such core “grows” increasingly more new particles, which leads to more heavy chemical elements – from carbon, nitrogen, oxygen, phosphorus to iron, lead and uranium.
Courtesy of http://english.pravda.ru