The Fate Of Gas Giants Orbiting Red Giant Stars

The Fate of Gas Giants Orbiting Red Giant Stars. As stars near the end of their —s, they undergo a transformative phase, swelling into red giants. This phase poses an existential threat to the planets in their orbits. The inner planets, including possibly Earth, will be engulfed by the sun’s expansion. However, the fate of gas giants, such as Jupiter, is more complex.

Researchers have discovered that some gas giants can survive this destructive phase. Two pathways have been identified: either the planets are initially at a great distance from their host star, or they migrate inward after the star has transitioned to a white dwarf. The discovery of exoplanets around white dwarfs has provided valuable insights into these pathways.

In 2011, astronomers found an exoplanet with a mass similar to that of Jupiter orbiting a white dwarf at an extremely wide orbit, approximately 2,500 astronomical units (au) away. This distance allowed the planet to remain unaffected by the star’s expansion. In contrast, a Jupiter-sized gas giant discovered in 2020 around a white dwarf is thought to have migrated inward after the star’s transition. Despite these findings, astronomers observe relatively few gas giants orbiting white dwarfs.

The question —: are these planets truly rare, or