A Giant Planet Defies Stellar Death
Earth’s sun will die eventually, which is a fact established by science. Stars exhaust their fuel, and the sun is predicted to enter its red giant phase in a few billion years. During this phase, it will expand and swallow nearby planets. According to NASA, Mercury and Venus might face this fate.
The potential future of Earth and our solar system, when the sun reaches this stage, has been long debated. Recently, astronomers observed a giant planet that survived the death of its star.
Study of Planetary Survival
Ryan J. MacDonald from the University of St Andrews led a study revealing that planets around a dying star move further away initially due to the reduced mass of the new white dwarf. However, one giant planet, WD 1856b, moved closer to the white dwarf billions of years after the star’s death. This movement was likely caused by two nearby red dwarf stars.
Astronomers identified this giant planet orbiting a white dwarf in 2020, sparking curiosity over how it survived the sun’s violent red giant phase. The new investigation, using NASA’s James Webb Space Telescope (JWST), analyzed the planet’s atmosphere and its journey.
Discovery and Analysis
JWST observations revealed methane and high-altitude hazes in the planet’s atmosphere. These findings mark the first successful characterization of the atmosphere of a planet transiting a dead star. This insight opens an avenue for studying planetary systems after their host stars die.
The study confirmed the planet originally orbited from a safe distance and moved closer only billions of years post-star death.
Implications for Our Solar System
Christopher O’Connor from Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics stated the study affects predictions for our solar system’s fate. In about five billion years, when our sun dies, it’s uncertain what happens to the planets. This research widens possibilities for habitable planets post-stellar collapse.
WD 1856b, located about 80 light-years from Earth, is a gas giant with a radius similar to Jupiter, orbiting a star the size of Earth. Post-collapse, sunlike stars become white dwarfs, their dense remnants.
Theories on Planet Migration
O’Connor described the planet as part of a “bizarre planetary system,” with a radius eight times that of the white dwarf and completing an orbit in 1.4 days. Survival through the star’s red giant phase is unexpected.
Two theories suggest either the planet survived being swallowed by the star or migrated toward it due to other objects’ gravitational effects. The white dwarf belongs to a triple star system, with outer stars potentially affecting WD 1856b’s orbit.
The NASA telescope helped investigate and revealed the planet’s unexpected heat, suggesting it heated as it moved closer, up to 5.5 billion years after becoming a white dwarf.
MacDonald contemplated our solar system’s giant planets possibly moving towards a white dwarf when the sun dies, influenced by gravitational interactions or another star’s flyby.
Looking Forward
This planet and star offer a preview of our sun’s eventual fate, said MacDonald. “It’s like using a time machine to look into the distant future of our solar system,” he noted.
The results show that stellar death is not definitive—planets might thrive post-star death.
Reference: MacDonald, R.J., O’Connor, C.E., Boehm, V.A. et al. Aerosols and hydrocarbons in the atmosphere of a white dwarf planet. Nature 655, 76–80 (2026). https://doi.org/10.1038/s41586-026-10514-7
Contact Newsweek editors on this story: Kara Dolman and James Debens.