WASP-12b endures scorching 4,000°F temperatures while orbiting its star in just one Earth day.
Key Takeaways
- Astronomers have confirmed that WASP-12b, a massive, egg-shaped exoplanet, is spiraling toward its star and will crash in around 3 million years.
- The intense gravity and extreme proximity to its star have turned WASP-12b into a distorted “hot Jupiter” with unique features like an egg-shaped form and a short orbit.
- WASP-12b’s rapid orbital decay is a rare phenomenon caused by tidal dissipation, puzzling researchers about the role of the star’s activity.
- Scientists found evidence of unexpected activity in the star, suggesting it may have reached the end of its hydrogen-burning phase, contradicting its main-sequence classification.
- This discovery could provide clues about the fates of other “hot Jupiters” and their potential collisions with their stars.
____________
A Death Spiral for WASP-12b
Astronomers have revealed that WASP-12b, a distant exoplanet twice the size of Jupiter, is on a collision course with its star, located 1,400 light-years from Earth. Previously estimated to survive another 10 million years, new calculations now predict a fiery crash within just 3 million years—a remarkably short timeframe compared to its star’s 3-billion-year age.
WASP-12b’s extreme proximity to its yellow dwarf star, a mere 2.1 million miles away, has given it the classification of an “ultra-hot Jupiter.” This results in a blistering surface temperature of 4,000°F (2,210°C). Its close orbit causes immense tidal forces, distorting the planet into an egg shape and stripping its material into a surrounding disk.
Insights Into Orbital Decay and Stellar Activity
Researchers used 12 years of transit observations from the Asiago Observatory in Italy to study WASP-12b’s orbital variations. The team concluded that the planet’s decay is caused by tidal dissipation, where gravitational forces between the star and planet convert orbital energy into heat, shrinking the orbit. However, the rapid decay rates suggest an anomaly: WASP-12’s behavior hints at an advanced stellar stage, yet analyses confirm it remains in its main sequence.
Unexpectedly, the star showed high activity levels, with sunspots and plasma outbursts that may accelerate WASP-12b’s disintegration. The findings open questions about whether other ultra-hot Jupiters share similar fates.
A Universal Phenomenon?
When WASP-12b eventually collides with its star, the resulting explosion will make the star hundreds of times brighter, albeit briefly—an event observable from Earth if humanity still exists millions of years from now. Lead researcher Pietro Leonardi suggests this dramatic fate might not be unique, as studies indicate fewer hot Jupiters exist around older stars.
The research team continues their investigation, now collaborating with the European Space Agency’s CHEOPS mission to measure orbital decay in other hot Jupiters. Leonardi believes their findings could help uncover whether these exoplanets’ fiery ends are a common feature of the universe.
The team’s research is published on the paper repository arXiv.
