Doomed giant planet caught in death spiral around its star — Can it survive?

The massive exoplanet TOI-2109b is spiralling into its host star, heading toward destruction. (Image: NASA/CXC/M. Weiss)

A distant gas giant, larger than Jupiter, is spiralling towards its death. TOI-2109b, as it’s named, has drawn attention from scientists worldwide.

A Planet on a Rapid Orbit

TOI-2109b is located 870 light-years from Earth. It orbits its host star in just 16 hours. This tight orbit makes it an “ultrahot Jupiter.” These planets are rare and extremely close to their stars. TOI-2109b is the closest known of its kind. It has around five times Jupiter’s mass. Scientists say it’s perfect for studying planetary destruction.

Researchers from Macquarie University led the new analysis. They reviewed telescope data from 2010 to 2024. Their findings confirm the planet’s orbit is slowly decaying. That means the planet is inching closer to its star. Over three years, its orbit may shrink by 10 seconds.

Three Possible Fates Ahead

One possible outcome is a fiery plunge into the star. If orbital decay speeds up, the star may absorb it completely. This could create a brief but bright flash of light. Another scenario involves powerful tidal forces. These forces might stretch and tear the planet apart. It would eventually become a distorted shape and disintegrate.

A third fate could allow the planet to survive. If intense radiation strips its gas layers, it may shrink. This would reveal a dense, rocky core beneath. The result might resemble a super-Earth or mini-Neptune. This outcome would mark a dramatic transformation, not destruction.

Clues to Planetary Evolution

TOI-2109b offers rare insights into planetary evolution. It shows how large planets behave near their stars. It could also help explain other unusual star systems. Researchers plan to monitor the planet over the coming years. The goal is to better understand orbital decay and planet-star interactions.

Their study, published in The Astrophysical Journal on July 15, continues to raise new questions. For now, TOI-2109b remains suspended between three possible destinies—each with big lessons for science.