When are elements heavier than iron formed by stars?
O in young stars
O as a star is first formed
O as a dying star explodes
O in small, old stars
Elements heavier than iron are formed in two main processes: supernovae explosions and neutron star mergers.
In supernovae explosions, elements heavier than iron are formed when a massive star runs out of fuel and undergoes a rapid collapse and explosion. This explosion releases a tremendous amount of energy, which causes the fusion of lighter elements into heavier ones.
Neutron star mergers occur when two neutron stars collide and merge. This collision produces a highly energetic event called a kilonova, which also leads to the formation of heavy elements.
Therefore, elements heavier than iron are formed during the explosive deaths of massive stars (supernovae) and during the collisions of neutron stars (neutron star mergers).