Gacrux system

The overabundance of the s-process element barium in the spectroscopy of Gacrux, the prominent red giant, suggests that it is orbited by a dim white dwarf companion. Though heavier than iron, trace amounts of s-process elements such as barium and technetium can be produced in even medium-mass red giants, themselves forged from the slight amount of heavy elements already present in the star. As Gacrux's likely companion star lost its outer layers a planetary nebula, it would have allowed Gacrux to accrete much of its lost mass.

Future

Eventually a point is reached when the core can no longer become smaller. The matter resists further contraction because of the electrons' mutual repulsion. What is left is known as a white dwarf star. The star will be extremely dense, only the size of a planet, but very hot, shining with a brilliant bluish-violet light, yet due to its small size it is very dim from a distance. White dwarfs continue to shine, eventually losing energy to space and cooling off.