Scientists have confirmed the existence of two brown dwarfs, Gliese 229 Ba and Gliese 229 Bb, orbiting close together around a small star.
This finding comes as a revelation to astronomers who first identified a brown dwarf in 1995, only to later realize that this object was not alone.
The two brown dwarfs are located just 19 light-years away from Earth in the constellation Lepus, making them relatively nearby in cosmic terms. A light-year, which is the distance light travels in a year, is about 5.9 trillion miles.
The brown dwarfs are bound together in a binary system, where they orbit each other every 12 days. They are only 16 times farther apart than the Earth is from its moon, a distance that is quite close for celestial bodies.
Sam Whitebook, a graduate student at Caltech and lead author of one of the studies, explained, "A brown dwarf is an entity that occupies the space between a planet and a star."
Two Unique Brown Dwarfs Redefine Cosmic Understanding
These brown dwarfs are massive-Gliese 229 Ba is 38 times the mass of Jupiter, while Gliese 229 Bb is 34 times that mass. However, both have smaller diameters than Jupiter due to their high density.
Brown dwarfs are unique because they do not have enough mass to ignite the nuclear fusion that powers stars. This is why they shine dimly compared to stars.
Whitebook noted that they can burn a heavy form of hydrogen, called deuterium, but not the basic form of hydrogen that stars use.
The discovery was made using advanced telescopes in Chile and Hawaii. Jerry Xuan, a Caltech astronomer and lead author of another study, said, "This discovery reveals that brown dwarfs can exhibit unusual configurations that took us by surprise."
Scientists had long suspected that Gliese 229 B could have a companion but had difficulty confirming it due to their faintness.
The study, published in the journal Nature, involved an international team of astronomers, including experts from NASA and the European Space Agency. The collaboration has opened new avenues for understanding brown dwarfs and their role in the universe.
