A team of astronomers has gathered compelling evidence suggesting that a star similar to our Sun might have consumed one of its own planets.
This star, identified as TOI-5882, is approximately 1,300 light-years away from Earth.
Scientists found that TOI-5882 contains an unusually high level of lithium, a chemical element that could indicate a significant event in the star’s history.
The idea that “you are what you eat” applies to stars as well. While stars naturally contain small amounts of lithium, planets tend to be much richer in this element.
When a star engulfs a planet, it can absorb a large dose of lithium, leaving behind a chemical signature. This process, known as “planetary engulfment,” occurs very rapidly on cosmic timescales—sometimes within days or weeks.
Because such events happen so quickly, astronomers rarely have the chance to observe a star swallowing a planet in real-time. Instead, they must piece together clues left behind long after the event.
Lead researcher Brooke Kotten from the University of Michigan explains that this investigative work is what makes the field so engaging. Since they can’t observe the “crime” directly, scientists analyze data to reconstruct what likely happened.
Studying these occurrences helps us understand how often stars consume planets and the various mechanisms behind it.
In the distant future, our own solar system might experience a similar fate. In about five billion years, the Sun is expected to swell into a red giant, potentially swallowing Mercury and Venus, and possibly even Earth.
However, TOI-5882 hasn’t expanded enough for that explanation to fit. Instead, scientists suspect that another object—the brown dwarf orbiting the star—may have played a role.
This brown dwarf is a massive object, over 20 times the mass of Jupiter, larger than planets but too small to become a true star. Researchers believe it might have disrupted the orbit of a nearby planet, eventually causing it to spiral into the star.
The scientists estimate that the planet likely had a mass somewhere between a few Earth masses and Neptune.
They used a technique called spectroscopy to study the light emitted by TOI-5882. Since different elements leave unique patterns in starlight, spectroscopy helps identify the chemical makeup of stars from great distances.
To confirm that TOI-5882’s lithium level was truly exceptional, the team compared it with 62 similar stars matching in age, size, and temperature. In all cases, TOI-5882 stood out—containing more lithium than at least 97% of the comparison stars.
Interestingly, a few other stars also showed higher-than-normal lithium levels, hinting that there may be additional ways for stars to become enriched with this element. While one mystery is solved, many new questions have arisen for astronomers to explore.
