A team of 14 researchers from the United States and Chile has uncovered evidence of a subgiant star consuming one of its planets. The star, designated TOI-5882, was already known to host a massive brown dwarf companion named TOI-5882 b, which may have played a role in destabilizing the planet's orbit.
This discovery marks a rare direct observation of planetary engulfment, a process that occurs when a planet spirals into its host star. The brown dwarf companion likely gravitationally nudged the planet onto a fatal, inward trajectory. The findings rely on stellar composition analysis, which revealed chemical signatures consistent with planetary material being absorbed.
TOI-5882 is a subgiant star, meaning it has begun evolving off the main sequence and expanding. This evolutionary stage can destabilize planetary systems, making engulfment more probable. The team used spectroscopic data from ground-based observatories to detect the enrichment of certain elements in the star's atmosphere, indicating recent consumption of rocky planetary material.
The event provides a glimpse into the violent end stages of planetary systems and underscores the role of stellar companions in shaping planetary fates. The research, published in a peer-reviewed journal, adds to a growing catalog of stars with evidence of ingesting their own worlds.
While the evidence is strong, some astronomers caution that the observed chemical anomalies could also result from other processes, such as interstellar accretion or internal stellar mixing. The exact timing and mechanics of the engulfment remain uncertain without direct imaging or follow-up observations.