A rare glimpse of a giant planet still “in the womb” with a mass nine times the mass of Jupiter | planets

Scientists observed a massive planet about nine times the mass of Jupiter in a remarkably early stage of formation – describing it as still in the womb – in a discovery that challenges current understanding of planet formation.

The researchers used the Subaru telescope near the summit of an inactive Hawaiian volcano and its orbit. Hubble Space Telescope To discover and study the planet AB Aurigae b, a gas giant that orbits unusually far from its young host star. Gas giants are planets, such as Jupiter and Saturn, the largest of the planets in our solar system, composed mostly of hydrogen and helium, with circular gases surrounding a smaller solid core.

“We think it’s still very early in the ‘birth’ process,” said astrophysicist Thane Currie of the Subaru Telescope and NASA Ames Research Center, lead author of the study published Monday in the journal. natural astronomy. “Evidence suggests that this is the first stage of the gas giant’s formation at all.”

It’s embedded in an expanding disk of gas and dust that holds the planet-forming material around and surrounds a star called AB Aurigae. It is located 508 light years from Earth. The star had a fleeting moment of fame when his image appeared in a scene in the 2021 movie Look Up.

About 5,000 planets outside our solar system, or exoplanets, have been identified. This is one of the biggest. It is close to maximum size to be classified as a planet rather than a brown dwarf, an intermediate body between a planet and a star. It is heated by gas and dust falling into it.

Forming planets – called protoplanets – have been observed around only one star.

Almost all known exoplanets have orbits around their stars within the distance between our Sun and the distant planet Neptune. But this planet orbits three times the distance of Neptune from the sun and 93 times the distance between the Earth and the sun.

Its birth appears to follow a different process than the standard planetary formation model.

“Conventional thinking is that most – if not all – planets form by the slow accumulation of solids in a rocky core, and that gas giants go through this stage before the solid core becomes massive enough to begin accreting gas,” the astronomer and colleagues said. – Author Oliver Guyon of Subaru Telescope and University of Arizona.

In this scenario, protoplanets embedded in the disk surrounding a young star gradually grow from dust into solid bodies the size of rocks, and if this core reaches the Earth’s mass several times, it begins to collect gas from the disk.

“This process cannot form giant planets at such a large orbital distance, so this discovery challenges our understanding of planet formation,” Guyon said.

Instead, the researchers believe that AB Aurigae b is forming in a scenario in which the disk surrounding the star cools and gravity causes it to splinter into one or more planetary masses.

“There is more than one way to cook an egg,” Corey said. “And it is clear that there may be more than one way to form a Jupiter-like planet.”

The star AB Aurigae is about 2.4 times larger than our Sun and about 60 times brighter. It’s about 2 million years old — a baby by star standards — compared to about 4.5 billion years old for our middle-aged sun. The sun at the beginning of its life was surrounded by a disk that led to the emergence of the Earth and other planets.

“New astronomical observations constantly challenge our current theories, ultimately improving our understanding of the universe,” Guyon said. “The formation of the planet is very complex and chaotic, with many surprises ahead.”