Scientists Discover Strange-Looking Binary Star with 3 Planet-Forming Rings

Scientists have observed a never-before-seen binary star with three planet-forming rings.

The universe is made up of stars surrounded by planets and planet-forming rings, as well as binary star systems where each of the two stars has its own rotating planetary disc, which is usually made of gas and dust.

But researchers from the University of Copenhagen's Niels Bohr Institute in Denmark have discovered an unusual binary star system: each star has its own planet-forming ring like the rest, with the addition of one giant shared ring.

"The two newly formed stars are both the size of our sun and they each have a rotating disc of gas and dust similar to the size of our solar system," Christian Brinch, assistant professor in the research group Astrophysics and Planetary Science and the Niels Bohr International Academy at the Niels Bohr Institute, said in a press release.

"In addition, they have a shared disc that is much larger and crosses over the other two discs. All three discs are staggered and this breaks with everything we have seen so far."

The binary star named IRS 43, which was about 400 light-years away from the Earth, was observed through the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in northern Chile. According to the scientists, the stars are estimated to be 100-200,000 years old and they may have already started forming planets. The planets are hidden by a cloud of dust and could not be seen directly, but through the ALMA telescope, the regions where they are forming could be traced.

The researchers conclude that all three discs were formed out of the same material. But they are unsure about how the two smaller discs had been formed. "Whether the two smaller discs formed by fragmenting the big disc or whether they are a result of material flowing in from the big disc is not entirely clear," Brinch said in a report by New Scientist.

"If the discs were born misaligned, the misalignment would be a result of the formation process itself, and therefore we would expect such systems to be very common. However, if the misalignment is a result of an ejected third star, systems like these would be rather rare," he added.

The three discs were also found to be "tumbling around" and are skewed relative to each other, compared with other systems where rotating discs lie flat. This led the researchers to think that the formation occurred in a turbulent manner.

Researchers will conduct computer simulations to understand the physics behind the formation process and will use the ALMA telescope to study the discs in higher resolution to get details about their chemical composition.