The researchers used the Subaru Telescope, near the top of an inactive Hawaiian volcano, and the Hubble Space Telescope to detect and study the planet called AB Aurigae b, a gas giant orbiting unusually far from its young star. Gas giants are planets, such as the largest in our solar system, Jupiter and Saturn, which consist mainly of hydrogen and helium, with swirling gases surrounding a smaller solid nucleus. “We believe it is still very early in the birth process,” said astrophysicist Thayne Currie of the Subaru Telescope and the Nasa-Ames Research Center, lead author of the study, which was published Monday in the journal Nature Astronomy. “Evidence shows that this is the oldest formation stage ever observed for a gas giant.” It is embedded in an extensive disk of gas and dust that carries planet-forming material and surrounds a star called AB Aurigae. It is 508 light-years from Earth. This star had a fleeting moment of fame when his image appeared on a stage in the 2021 Don’t Look Up movie. An artist’s illustration shows a huge, newly formed exoplanet called AB Aurigae b. Photo: NASA / Reuters About 5,000 planets, or extraterrestrials, have been identified beyond our solar system. This is one of the biggest. Approaching the maximum size that should be classified as a planet and not as a brown dwarf, a body in between a planet and a star. It is heated by gas and dust that falls into it. Planets in the process of formation – called protoplanets – have been observed around just one other star. Almost all known exoplanets have orbits around their stars within the distance that separates our sun and the most distant planet of Poseidon. But this planet orbits three times farther from Poseidon than the sun and 93 times the distance of the Earth from the sun. His birth seems to follow a different process from the typical planetary formation model. “The conventional thinking is that most – if not all – of the planets are formed by the slow accumulation of solids in a rocky core, and that the gas giants go through this phase before the solid nucleus becomes massive enough for gas to begin to accumulate,” the astronomer said. and study partner. -author Olivier Guyon of the Subaru Telescope and the University of Arizona. In this scenario, the protoplanets embedded in the disk surrounding a young star gradually grow from solid blocks the size of a boulder, and if this nucleus reaches the mass of the Earth many times, then they begin to accumulate gas from the disk. “This process cannot form giant planets at great orbital distances, so this discovery calls into question our understanding of planet formation,” Guyon said. Instead, researchers believe that AB Aurigae b is formed in a scenario in which the disk around the star cools and gravity causes it to fragment into one or more massive clusters formed on planets. “There is more than one way to cook an egg,” Currie said. “And obviously there can be more than one way to form a planet like Jupiter.” The star AB Aurigae is about 2.4 times more massive than our sun and almost 60 times brighter. It is about 2 million years old – an infant by astronomical standards – compared to about 4.5 billion years for our middle-aged sun. The sun early in his life was also surrounded by a disk that created the Earth and the other planets. “New astronomical observations are constantly challenging our current theories, ultimately improving our understanding of the universe,” Guyon said. “The formation of the planet is very complicated and messy, with many surprises still ahead of us.”
