Scientists find massive planet 10 times bigger than Jupiter that shouldn’t exist

Scientists have found an “alien world” that is almost 10 times bigger than Jupiter, prompting speculation about the planet’s origins.

The mysterious new giant gas planet is one of the heaviest ever found and was discovered in the Centaurus constellation about 325 light years away, revealed a new study published in the journal Nature on Wednesday.

The planet, named b Centauri b, was found orbiting b Centauri, a two-star system with a mass at least six times that of the Sun. It is the hottest and largest planet-hosting system known to date.

Until now, astronomers said no planets had been spotted around a star more than three times as big as the Sun, making it by far the largest system around which a planet has been discovered.

“The planet in b Centauri is an alien world in an environment that is completely different from what we experience here on Earth and in our Solar System,” the study’s co-author Gayathri Viswanath, a PhD candidate at Stockholm University, said in a statement.

“It’s a harsh environment, dominated by extreme radiation, where everything is on a gigantic scale: the stars are bigger, the planet is bigger, the distances are bigger,” Ms Viswanath added.

“Finding a planet around b Centauri was very exciting since it completely changes the picture about massive stars as planet hosts,” said Markus Janson, another co-author and an astronomer at the Stockholm University.

The main star in this system is a so-called B-type star, over three times as hot as the Sun and very luminous.

Due to its intense temperature, astronomers said it emits large amounts of ultraviolet and X-ray radiation that should work against the formation of planets.

“B-type stars are generally considered as quite destructive and dangerous environments, so it was believed that it should be exceedingly difficult to form large planets around them,” Dr Janson said.

But the latest discovery showed that even star systems releasing such intense amounts of radiation can support planet formation.

The scientists believe the trajectory of the massive planet around the central pair of stars could be key to its survival.

It moves around the star system in one of the widest orbits yet discovered, a staggering distance that is 100 times greater than the one between Jupiter and the Sun.

“The planet-to-star mass ratio of 0.10–0.17 per cent is similar to the Jupiter–Sun ratio, but the separation of the detected planet is about 100 times wider than that of Jupiter,” the scientists wrote in the study.

“Our results show that planets can reside in much more massive stellar systems than what would be expected from extrapolation of previous results,” they added.

The findings were made using the sophisticated Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) mounted on the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile.

The astronomers pointed out that the planet may have not formed conventionally.

They speculate it could have formed elsewhere and arrived at its present location or could have formed via gravitational instability.

Using ESO’s Extremely Large Telescope (ELT), scheduled to start observations later this decade, the researchers hope to shed more details on the new planet.

“It will be an intriguing task to try to figure out how it might have formed, which is a mystery at the moment,” Dr Janson noted.