What the VLT’s four linked mirrors had really detected was a subtle ‘twist’, where two spirals intersect in a swirling disc of dust and gas orbiting the young star AB Aurigae, 520 light years from Earth. , in a constellation known as The Charioteer. It was, according to theory and these preliminary observations, the place in this cosmic maelstrom where a future planet first merged into growing mass, like a seed, only to globalize into other pieces and accumulate enough gravity to spin over eons in a sphere. planet.
More than an irresistible metaphor, the announcement of the “little planet” reminded us that the science of the cosmos has always raised the deepest and oldest human questions: what is the world? Where is he from? Are there others?
The tech frontier has moved a step further this week, with the release of new research from the VLT that shows the very first images of what you might think of not as a baby but as a pair of twin planets, two gas giants in orbit. distant. around a young star. It is the first time that such a celestial system has been directly imagined.
These two exoplanets, as the planets around other stars are called, are larger than the gas giants of the solar system Jupiter or Saturn, and orbit their star, called TYC 8998-760-1, at much greater distances. that these planets orbit the Sun.
These planets orbit 160 and 320 times the distance between the Earth and the Sun, compared to about five and ten times for Jupiter and Saturn. They are also huge, six and 14 times the mass of Jupiter.
The new images mark the first time that such a double exoplanetary system has been observed around a young star, this one about 17 million years old, compared to more than four billion for the Sun.
“This discovery is a snapshot of an environment that is very similar to our solar system, but at a much earlier stage of its evolution,” said Alexander Bohn, doctoral researcher at Leiden University, who led the research.
There have only been two other such systems ever discovered: one with four giant planets, one with at least two “accretion protoplanets”.
Observing these orbits through telescopes, using devices capable of removing light from surrounding stars, offers a rare opportunity to test theories of the dynamics of planetary formation in the real world. It also helps explain the origin of Earth itself, which is believed to have come together from a swirling disk of dust orbiting the Sun, ultimately absorbing the mass of infalling asteroids, even after enduring the collision. of another whole planet, called Theia, which reversed Earth’s orbit by 23 degrees and splashed the rock that became the Moon.
Théia was absorbed by the Earth, according to the theory, and other planets are also “dead”. For example, these theories of planetary formation explain such wonderful phenomena as the asteroid Almahata Sitta, which fell from space in the Nubian Desert of northern Sudan in 2008, followed all the way by an astronomer, and then recovered. , only to produce massive diamonds which are believed to have formed inside a long lost planet.
The sheer size of the diamonds was evidence of the presence of this planet, which is believed to have collided with another, with its remains either absorbed, burnt in the Sun, or possibly escaping orbit in outer space, leaving behind just this little asteroid that eventually fell. To the earth.
Watching this process in its stages of formation is a scientific luxury that has so far escaped astronomers.
“These multi-planetary systems are intriguing laboratories for studying the dynamic interactions and scattering events between multiple planetary mass companions, which is crucial for understanding the formation and dynamic evolution of planetary systems,” said an article in The Astrophysical Journal Letters, reporting the results of a research group headed outside of Leiden University in the Netherlands, called the Young Suns Exoplanet Survey.