A very large star of high luminosity and low surface temperature. Red giants are thought to be in a late stage of evolution when no hydrogen remains in the core to fuel nuclear fusion.
- ‘It is believed that eventually the sun will expand into a red giant, swallowing all of the inner planets, and destroying all life on earth.’
- ‘When its fuel runs out, an old star expands into a red giant and then collapses to become a white dwarf.’
- ‘Multiple collisions involving red giants and other stars might yield the random orbits her team has observed.’
- ‘It will then turn into a swollen red giant, burning to a frazzle any life left here on Earth.’
- ‘About a billion years before a sun-like star ‘dies,’ or stops generating energy via nuclear fusion, it becomes a red giant, growing dramatically to a hundred times its original diameter.’