For the first time, researchers from the Space Research Institute in Baltimore have studied two exoplanets orbiting white dwarf stars, the dead cores of sunlike stars. The findings were published through arXiv, an open-access portal for scientific papers, and mark a milestone in the observation of planetary bodies around stellar remnants. This advance comes from a collaborative effort that leverages the unparalleled sensitivity of space-based observatories to push the boundaries of what we know about planetary systems after their stars fade away.
The team conducted their observations with the James Webb Space Telescope, whose infrared capabilities allow a closer look at faint, distant worlds. In the data, two planetary systems emerged, each centered on a white dwarf. These ancient stars have exhausted their nuclear fuel and shed their outer layers, leaving behind dense cores that illuminate the surrounding space with a quiet glow. The discovery provides a rare glimpse into planetary configurations that survive and evolve long after a star’s main sequence has ended.
Lead author Susan Mullaly summarized the significance by noting that very few planets have been detected orbiting white dwarfs to date. The newly identified planets resemble the outer members of our own solar system in several respects, offering tangible evidence of a planetary system that persists beyond the star’s death. This finding gives scientists the first concrete view of how planetary architectures might appear once a star’s light has dimmed, and it prompts new questions about long-term planetary stability and evolution in aging stellar environments.
In the Webb imagery, the planets orbited the white dwarfs designated WD 1202-232 and WD 2105-82. One of the outer planets sits at an enormous distance from its host star, about 11.5 astronomical units away—roughly equivalent to the distance of Saturn from the Sun in our own system—while the other signals a much farther orbit at about 34.5 astronomical units. These wide separations imply that, even as the star dies and contracts, substantial planetary primes can endure in wide, stable paths, potentially shielded from the most intense phases of stellar evolution.
Estimates for the planetary masses place them in a broad range, from roughly one to seven times the mass of Jupiter. While precise measurements remain to be refined, the current assessment suggests substantial gas envelopes and dynamic interactions with their white dwarf hosts. The configurations observed hint at complex formation histories and possible past migrations that enabled these planets to reach their present orbits, even as their stellar environment changed dramatically over time.
Looking ahead, astronomers note that if the Sun were to become a white dwarf after about five million years, a fate shared by Mercury, Venus, Earth, and Mars under certain models, our own solar system might eventually resemble these distant systems. The ongoing study of WD 1202-232 and WD 2105-82 helps frame predictions about how planetary systems endure, rearrange, or dissolve as their central stars transition to their final stages, an area of active investigation that blends stellar evolution with planetary dynamics. This work stands as a vivid reminder that the cosmos keeps surprising us with resilient worlds hiding in plain sight around stars that once shone brightly for billions of years.
Some in the field have long wondered about the risk of encounters with rogue, or stray, stars and what such events might mean for the solar system’s future. The recent discoveries contribute valuable context to that discussion, offering empirical data points to model gravitational interactions in crowded stellar neighborhoods. By examining these distant remnants and their orbiting companions, scientists at large continue to map the resilience of planetary bodies against the changing tides of their host stars, pushing toward a more complete picture of planetary survivability across cosmic time.