Title: Astronomers Unveil the First Verified Planet in an Orthogonal Orbit Around Binary Brown Dwarfs
In a remarkable astronomical finding that questions traditional theories of planetary system development, a group of researchers has identified the first confirmed planet orbiting at a right angle to its parent stars. The planet, referred to as 2M1510 (AB) b, is located within a binary system made up of two brown dwarfs—cosmic entities that lie between the classifications of planets and stars.
This groundbreaking discovery, achieved using the European Southern Observatory’s Very Large Telescope (VLT) in Chile, showcases a planet moving in a polar orbit — specifically, an orbit that is perpendicular (90 degrees) to the orbital plane of its two brown dwarf hosts. This arrangement had been speculated for a long time but had never been substantiated through observation until now.
An Accidental Finding
The research was spearheaded by Thomas Baycroft, a doctoral student at the University of Birmingham, as part of efforts to enhance measurements of a rare eclipsing brown dwarf pair. Utilizing the Ultraviolet and Visual Echelle Spectrograph (UVES) on the VLT, the research team detected gravitational signals that were incompatible with the two brown dwarfs alone. After ruling out alternative explanations, they concluded that the most reasonable inference was the existence of a third body—a planet—traversing a perpendicular orbit.
“The finding was unexpected,” remarked co-author Amaury Triaud, a professor at the University of Birmingham and one of the lead researchers of the study. “Our observations were not initially focused on discovering such a planet.”
Brown Dwarfs: The Link Between Stars and Planets
Brown dwarfs are frequently called “failed stars” because they have more mass than gas giants like Jupiter but lack the necessary nuclear fusion to radiate light like standard stars. The system examined, identified as 2MASS J15104786+1329486 (commonly known as 2M1510), is one of only two known systems where brown dwarfs eclipse each other from the perspective of Earth—making it an excellent candidate for precise observations.
This newly identified planetary companion adds further uniqueness to an already rare system. It marks the first instance where scientists have observed a planet orbiting around brown dwarfs in a nearly vertical orbital trajectory — traversing over the poles of the stellar duo, as opposed to aligning with their equatorial plane.
Comprehending Perpendicular Orbits
In most known binary systems, planets typically orbit within the same plane as the orbital paths of their host stars—similar to how the planets in our solar system largely align with the Sun’s equator. The polar arrangement seen in 2M1510 (AB) b significantly deviates from this standard and paves the way for fresh insights into planet formation.
Theoretical models had previously indicated that gas and dust could create circumstellar discs that are orthogonal to the orbital paths of binary systems—suggesting a potential basis for planet formation in such orientations. Until now, however, no planet had been confirmed in this distinctive alignment.
“This confirmation lends substantial credibility to the notion that planetary systems can arise in a far broader spectrum of configurations than traditional models propose,” emphasized Triaud.
Planet Structure and Attributes
While the planet 2M1510 (AB) b has yet to be directly imaged or fully described, scientists estimate its mass to be around 10 times that of Earth if it orbits close to the gravitational stability threshold of the binary stars. It is anticipated to complete an orbit roughly every 100 days, though additional observations are required to fine-tune these estimates.
The research team aims to conduct further investigations to more accurately assess the planet’s orbital period and mass. These studies could also shed light on the long-term stability of the system and whether the peculiar orbit influences the planet’s atmosphere and temperature.
Consequences for Exoplanet Research
The discovery of this polar orbit significantly expands the range of environments where exoplanets might be found. It challenges conventional assumptions that planetary systems only form along the equatorial planes of stars or binary pairs. Furthermore, it implies that the processes that generate planetary systems can differ widely, influenced by initial conditions and gravitational dynamics.
“It illustrates the extensive variety the Universe can produce,” said Triaud. “The discovery of more of these unique arrangements emphasizes how much remains to be explored about our cosmic surroundings.”
The 2M1510 system is relatively nearby by astronomical standards, making it an ideal candidate for future detailed studies with other high-resolution instruments, including those on board space telescopes.
Published in Science Advances, the research includes input from the University of Birmingham, University of Cambridge, and various global research organizations. The team hopes their finding will encourage further investigations into non-coplanar planetary systems and motivate astronomers to step outside conventional models when searching for new worlds.
As planetary science continues to evolve, findings like 2M1510 (AB) b highlight the intricacy and diversity of planetary systems within our universe—and fuel renewed curiosity about what else remains to be discovered.