Produced by: Tarun Mishra Designed by: Manoj Kumar
In 1995, astronomers confirmed the discovery of Gliese 229B, believed to be a single brown dwarf. Brown dwarfs are celestial objects larger than planets but too small to ignite nuclear fusion like stars.
Recent observations, however, reveal that Gliese 229B is actually two brown dwarfs orbiting each other closely, forming a binary system. This was confirmed through studies using telescopes in Chile and Hawaii.
The two brown dwarfs, now designated as Gliese 229Ba and Gliese 229Bb, are gravitationally locked and orbit around a common star, a red dwarf, at an extremely close distance.
The two brown dwarfs orbit each other every 12 days, maintaining a separation only 16 times the distance between Earth and the Moon. Such close-orbiting brown dwarfs are rare, with only one other known pair.
Gliese 229Ba has a mass 38 times greater than Jupiter, while Gliese 229Bb has a mass 34 times that of Jupiter. Despite being more massive, they are smaller in diameter due to their density.
Brown dwarfs sit between planets and stars. They are not massive enough to sustain hydrogen fusion like stars but are heavier than large planets. They burn deuterium, a heavy form of hydrogen, but cool and dim over time.
Initial observations of Gliese 229B’s mass in 1995, around 71 times that of Jupiter, puzzled scientists because an object of that size should have been brighter. The discovery of two separate brown dwarfs resolves this inconsistency.
The discovery highlights the complexity of star and brown dwarf formation. Scientists remain unsure about the precise transition between giant planets and brown dwarfs, and this new configuration adds to the understanding of star formation processes.