KEY POINTS

  • Astronomers accidentally discovered a binary brown dwarf system
  • They were originally looking for potentially habitable planets
  • The brown dwarfs were eclipsing one another

A team of astronomers made an accidental discovery while they were searching for potentially habitable alien planets. While observing the universe, they came across a system of brown dwarfs that were eclipsing one another.

Brown dwarfs are massive cosmic objects that fall in between the definition of a planet and a star. Many scientists refer to them as failed stars because they are too small to be considered as stellar objects. On the other hand, brown dwarfs are too massive to be referred to as planets.

Although brown dwarfs are not uncommon in space, spotting a pair operating within the same system is quite rare. Recently, an international team of astronomers accidentally came across a binary dwarf star system while working on a project known as the Search for habitable Planets EClipsing ULtra-cOOl Stars (SPECULOOS). They presented their findings in a study published in the journal Nature.

As its name suggests, SPECULOOS involved the search for possible habitable planets. In other to find these kinds of worlds, the astronomers looked for stars and brown dwarfs being orbited by planets. One of the cosmic objects they focused on during their observations was the brown dwarf known as 2M1510.

While the astronomers were watching 2M1510, they noticed that it had a strange appearance. In addition, its brightness dimmed for about 90 minutes. Follow-up observations revealed that 2M1510 was actually being orbited by another brown dwarf. They explained that the decrease in 2M1510’s brightness was caused by the other brown dwarf eclipsing it.

“We rapidly realized that we were probably looking at two eclipsing brown dwarfs, one passing in front of the other, a configuration which is much rarer than planetary systems,” Artem Burdanov, the co-author of a new study conducted on the binary brown dwarf system said in a statement.

According to the astronomers, studying brown dwarfs can provide important information regarding the formation of both stars and planets. Due to their unique characteristics, brown dwarfs are like the missing link between small stars known as red dwarfs and gas giant planets such as Jupiter.

“Collecting a combination of mass, radius, and age is really rare for a star, let alone for a brown dwarf,” the study’s co-author Amaury Triaud said in a statement. “Usually one or more of these measurements is missing.”

Brown Dwarf
Artist’s conception of a brown dwarf, featuring the cloudy atmosphere of a planet and the residual light of an almost-star. NASA/ESA/JPL