Astronomers have made a groundbreaking discovery, finding an exoplanet orbiting a pair of brown dwarf stars in an unusual perpendicular configuration.
Astronomers have made a groundbreaking discovery, finding an exoplanet orbiting a pair of brown dwarf stars in an unusual perpendicular configuration. The two brown dwarfs, which are small and dim, follow orbits that cause them to eclipse each other when viewed from Earth.
A brown dwarf binary system consists of two brown dwarfs, which are objects that do not have enough mass to sustain nuclear fusion in their cores.
These systems can be formed when a star and a brown dwarf form together from the same molecular cloud.
The properties of brown dwarf binaries are influenced by their formation mechanisms, with some systems exhibiting synchronized rotation periods.
Research has shown that about 10% of nearby stars are part of a binary system, with many of these being brown dwarf pairs.
The Brown Dwarf Binary System
This is the first time researchers have observed an eclipsing brown dwarf binary system, making this discovery even more significant. Brown dwarfs are rare objects that cannot sustain nuclear fusion, resulting in their dim appearance. ‘They don’t shine like stars’ said one expert. The unusual configuration of the two stars has led to the detection of a planet-sized object orbiting them perpendicularly.
Brown dwarfs are celestial objects that share characteristics with both stars and planets.
They have enough mass to sustain nuclear fusion in their cores, but not enough to sustain it long-term, making them neither fully stars nor fully planets.
Brown dwarfs are formed when a region of gas collapses, but the collapse is halted before the object reaches the necessary temperature and pressure to ignite sustained nuclear fusion.
As a result, brown dwarfs emit very little light, making them difficult to detect.
A Rare and Unexpected Discovery
The team, led by Amaury Triaud at the University of Birmingham, carefully analyzed data collected by the Very Large Telescope in Chile to determine the masses of the stars and their movements. They found an unexpected signal in the data that could only be explained by a planet-sized object orbiting the two stars.
2M1510 (AB) b is a super-Earth exoplanet orbiting the ultracool dwarf star 2M1510 AB.
Located approximately 33 light-years from Earth, this small planet has a mass about 3 times that of our own Earth and orbits its host star within a mere 1.4 days.
The surface temperature of 2M1510 (AB) b is estimated to be around 430°C due to the intense radiation it receives from its parent star.
Perpendicular Orbits: Not Completely Unheard of
While perpendicular orbits are not unheard of, Triaud notes that they were never expected to occur in this context. The rarity of brown dwarfs and eclipsing pairs makes it challenging to make precise measurements.
A Harmonograph in the Sky
Katherine Blundell at the University of Oxford describes the system as a ‘harmonograph’ in the sky, highlighting its beauty and uniqueness. “It’s like a beautiful mathematical drawing come to life”. Studying how the two stars eclipse each other will provide valuable insights into the motion of this peculiar trio going forward.
Comparing to Science Fiction
The exoplanet 2M1510 (AB) b’s orbit around its two dim suns is reminiscent of the desert world Tatooine from Star Wars, but with a twist. The surface of 2M1510 (AB) b would experience a unique double dose of moonlight due to the dimmer nature of its stars.
The discovery of this exoplanet marks an exciting development in our understanding of the universe’s diversity and complexity. As astronomer Katherine Blundell puts it, ‘Twenty years ago, such configurations were considered science fiction, but now they have become science fact’
- newscientist.com | Exoplanet found in odd perpendicular orbit to brown dwarf star pair
