An illustration of the planet 2MASS J2126 and its host star TYC 9486-927-1, the largest solar system in the universe. Photo by University of Hertfordshire / Neil Cook

HERTFORDSHIRE, England, Jan. 27 (UPI) -- An international team of astronomers has identified the largest solar system in the universe.

It turns out an object previously thought to be unattached and lost in space is actually orbiting a distant star. The planet and star are more than 620 billion miles apart -- 7,000 times farther apart than the sun and Earth.


2MASS J2126 was first spotted several years ago. Researchers from the United States believed it to be either a failed star or a free-floating planet. A failed star, or brown dwarf, is a gas sphere not quite massive enough to generate fusion.

Size and age help astronomers differentiate gas giants from brown dwarfs, but scientists continue to disagree on the distinction between a large gas giant and a small brown dwarf.

A team of Canadian astronomers determined that 2MASS J2126 was on the low end of the brown dwarf scale -- small enough and young enough to be a rogue planet, a gas giant expelled from its home into interstellar space.

A group of scientists in England took a third look at the object and discovered a link with a distant star. Their calculations showed that 2MASS J2126 and TYC 9486-927-1 were moving through space at the same speed and on a similar trajectory, suggesting they are related.

"This is the widest planet system found so far and both the members of it have been known for eight years, but nobody had made the link between the objects before," Niall Deacon, an astronomer at the University of Hertfordshire, said in a press release. "The planet is not quite as lonely as we first thought, but it's certainly in a very long distance relationship."

By measuring the strength of the host star's lithium, astronomers determined it to be between 10 million and 45 million years old. The star's age allowed scientists to estimate the mass of 2MASS J2126, which they pegged at somewhere between 11.6 to 15 times the mass of Jupiter.

The object takes 900,000 years to complete a single orbit around its star. Over the course of its lifetime, 2MASS J2126 has completed fewer than 50 orbits.

The new record-setting star-planet duo is described in a new paper forthcoming the Monthly Notices of the Royal Astronomical Society.