Astronomers have discovered the first evidence that small red dwarf stars can devour their own planets [1].
This discovery changes the understanding of planetary survival around the most common type of star in the galaxy. If red dwarfs frequently consume their orbiting bodies, the likelihood of finding stable, habitable worlds in these systems may be lower than previously estimated.
Researchers observed six red dwarf stars [3] located in three stellar nurseries relatively close to the Sun’s region of the Milky Way [4]. The stars exhibited specific lithium signatures in their spectra, which indicates they have ingested rocky, Earth-like planets [4]. Because lithium is typically destroyed in the hot interiors of stars, its presence suggests a recent external addition of material [4].
These planetary consumption events are estimated to have occurred between 50 and 200 million years ago [2]. The evidence suggests that red dwarfs can violently consume nearby planets, effectively acting as cosmic killers of their own planetary systems [1].
While red dwarfs are smaller and cooler than the Sun, their volatile nature can lead to the destruction of nearby worlds. The detection of these signatures allows astronomers to track the history of planetary systems that no longer exist in their original form [4].
“Astronomers have discovered the first evidence that small red dwarf stars can devour their own planets.”
The discovery of planetary ingestion in red dwarf systems suggests that the 'habitable zone' around these stars may be a precarious location. Since red dwarfs are the most numerous stars in the Milky Way, the fact that they can devour Earth-like planets implies that the long-term stability required for life to evolve may be rarer than current models suggest.
