Scientists have discovered a planet that managed to survive the red giant phase of its star, providing hope for the future of Earth. According to recent data, in six billion years, the sun will expand and absorb Mercury, possibly Venus, and maybe even Earth. However, the finding of this planet that endured a similar process is a source of optimism, despite the possibility that Earth may be uninhabitable by then.
Researchers have detected a planet orbiting a white dwarf – the remnants of a star that has burned all its fuel. This planet may have once orbited at a distance similar to that of Earth from the sun before being pushed into a more distant orbit before the star could engulf it. This marks the first observation of a rocky planet in orbit around a white dwarf.
The discovery of this planet was made using telescopes from South Korea in 2020 through microlensing, a phenomenon where light from a distant star is intensified by another star passing in front. Although this observation was unique and brief, limiting further study until more powerful telescopes are available, scientists confirmed in 2023 that the planet’s host star is indeed a white dwarf.
Study results indicate that the planet has a mass approximately 1.9 times that of Earth and is located close to its star, suggesting it may be rocky. Previous findings around white dwarfs involved gas giants either in more distant orbits or that migrated inward after the star’s red giant phase. If confirmed, this would be the first evidence of a rocky planet surviving a star’s evolutionary stages.
Analysis of the star system’s evolution suggests that this planet likely resided in a zone resembling Earth’s habitable zone and managed to escape absorption when its star expanded into a red giant. As NASA plans to launch the new Nancy Grace Roman telescope in 2027, astronomers hope to discover more planets that have survived the red giant phase.