What Planet Is Being Eaten by Its Own Star?

WASP-12b is an exoplanet currently being stretched into an egg shape and slowly consumed by its host star, with material actively streaming from the planet’s surface into the star’s gravitational embrace.

The Doomed World of WASP-12b

Located approximately 1,400 light-years away in the constellation Auriga, WASP-12b represents one of the most extreme planetary death scenarios ever observed. This gas giant orbits so close to its host star that it completes a full orbit in just 26 hours—less than two Earth days. The intense gravitational forces from its star have distorted the planet from its original spherical shape into an elongated, egg-like form.

The Hubble Space Telescope has confirmed that material is continuously being stripped from WASP-12b’s atmosphere, forming an accretion disk around the star. This process, known as Roche lobe overflow, occurs when a planet ventures too close to its star and crosses the Roche limit—the point where tidal forces overcome the planet’s own gravity.

A World Darker Than Asphalt

One of WASP-12b’s most striking characteristics is its extraordinary darkness. The planet reflects less than 6% of the light that hits it, absorbing over 94% of incoming radiation. This makes it darker than asphalt and one of the darkest exoplanets ever discovered. The extreme heat from its proximity to the star—with temperatures exceeding 2,500°C (4,500°F)—likely contributes to this light-absorbing property by breaking down atmospheric compounds that would normally reflect light.

The Shrinking Orbit and Ultimate Fate

Astronomers have precisely measured WASP-12b’s orbital decay, finding that its orbit shrinks by approximately 29 milliseconds each year. While this may seem insignificant, it represents a steady spiral toward complete destruction. At this rate of decay, scientists estimate that WASP-12b will be entirely consumed by its star within roughly 3 million years.

This timeline makes WASP-12b a unique laboratory for studying planetary destruction in real-time. The planet’s demise offers insights into the extreme conditions that planets can endure and the various ways planetary systems can evolve—or end.

Scientific Significance

The study of WASP-12b has revolutionized our understanding of hot Jupiter exoplanets and their interactions with host stars. The planet’s extreme properties challenge existing models of planetary atmospheres and provide crucial data about how matter behaves under such intense conditions. Observations of this system help astronomers better understand the diversity of planetary fates and the complex gravitational dynamics that govern planetary systems throughout the universe.

WASP-12b serves as a stark reminder of the violent and dynamic nature of our cosmos, where even entire worlds can be slowly erased by the very stars they orbit.