First Polar-Orbit Planet Discovered Around Brown Dwarfs
WASHINGTON — In a groundbreaking astronomical discovery, scientists have identified the first known planet in a polar orbit around a pair of brown dwarfs. This unusual planetary system lies just 120 light-years from Earth and defies previously observed planetary behavior.
A Unique Planetary System Identified
Researchers using the Very Large Telescope in Chile, operated by the European Southern Observatory, have detected a gas planet named 2M1510 (AB) b. It is believed to be four to five times the mass of Earth. However, what sets this planet apart is not its size, but its orbit and the nature of its host bodies.
- The planet orbits two brown dwarfs, not conventional stars.
- Brown dwarfs are celestial objects too massive to be planets but not massive enough to sustain nuclear fusion like stars.
- The two brown dwarfs are tightly bound, orbiting each other at just 4% of the Earth-Sun distance.
Unusual Orbit: A Polar Path
Unlike typical planets in binary systems, which usually orbit in the same plane as the two host objects, 2M1510 (AB) b follows a polar orbit—almost perpendicular to the orbital plane of the brown dwarfs.
- The orbit lasts at least 100 days.
- It is the first confirmed polar orbit for a planet in a binary brown dwarf system.
- Previously, polar-orbit exoplanets had only been observed around single stars.
A Rarity Among Exoplanets
Out of the 5,800+ confirmed exoplanets, only 16 have been found in circumbinary orbits—those that circle two stellar bodies. This new planet is the first to do so around brown dwarfs, making it an exceptional find.
- The two brown dwarfs are each 35 times more massive than Jupiter.
- They are also much fainter than the Sun, emitting only 0.1% of its light.
- A third brown dwarf exists in the system but is too distant to affect the planet’s orbit.
Scientific Significance of the Discovery
This discovery supports long-standing hypotheses about planetary dynamics and offers new insights into the variety of planetary systems in the universe.
“This appears like an exotic configuration for a planetary system,” said Amaury Triaud, co-author and astrophysicist at the University of Birmingham.
“Probably the most important discovery since the first exoplanet has been how diverse planetary systems are. They seem to defy our expectations.”
Lead author Thomas Baycroft, a PhD student in astronomy at the same university, added that while polar orbits are familiar in artificial satellites around Earth, this is the first such evidence of a natural polar orbit in a binary system.
A Real-Life Tatooine? Not Quite
Though the scene may remind some of Luke Skywalker’s twin-sunset view on Tatooine from Star Wars, the experience on 2M1510 (AB) b would be quite different.
- Both brown dwarfs appear as faint red objects, not bright stars.
- The sky would be dimmer due to the low luminosity of the brown dwarfs.
- The light experienced on the planet would be significantly weaker than sunlight on Earth.
Conclusion
The discovery of 2M1510 (AB) b marks a milestone in astronomy. It not only confirms the possibility of polar orbits in circumbinary systems but also expands our understanding of how planetary systems form and evolve in extreme conditions.
