Over the last 30 years, astronomers have found more than 5,000 exoplanets, an eclectic collection of worlds far from our stellar neighborhood. The last of these could just be a baby.
Scientists announced Tuesday in the journal The Astrophysical Journal Letters, have convincing evidence for the existence of a world only 1.5 million years oldwhich makes it on one of the youngest planets ever found, perhaps the youngest.
This world—located in the constellation Ophiuchus, 395 light-years from Earth—is so young that its foundations of gas and dust are just coming together. This planet is a newborn rocking in the arms of its parent star..
“It’s like seeing our own past”, he opined Myriam Benistyan astronomer at the Institute of Planetology and Astrophysics of Grenoble in France and co-author of the study.
Because the suspected planet is covered in the matter that is making it, more telescopic observations will be needed to confirm its existence. By assuming it’s not rocky debris masquerading as a planet, scientists can use it to better understand how worlds form.
The torrent of newly discovered exoplanets has complicated or refuted traditional theories of planet formation. However, the location of this baby planet — nestled firmly within the disk of primordial matter around its star — supports the idea that most planets spend much of their lives growing up in a similar kind of nursery.
The discovery of the heavenly seed suggests that “all planetary systems have a common formation process”commented Anders Johanssen, an astronomer at Lund University in Sweden, who was not involved in the study. According to Johansen, despite the chaos of the cosmos, “there is actually a lot of order” when it comes to the creation of the planets.
The team of scientists used the radio telescope, located in Chile and made up of a collection of 66 antennas that act in unison, which is part of the astronomical project known as Atacama Large Millimeter/submillimeter Array (or ALMA), to gather evidence of this extremely young world. Gas and dust orbit certain stars in so-called circumstellar disks. This matter, which clumps together to form planets within these disks, emits radio waves that the ALMA radio telescope can detect.
Last year, Benisty and his colleagues used the radio telescope to make the first unambiguous detection of a halo of gas and dust orbiting an exoplanet: a circumplanetary foundry that is still making the world it covers and maybe some moons too.
For the latest study, they pointed the ALMA radio telescope at AS 209, a star slightly heavier than the Sun. At only 1.5 million years old, it has only recently started burning hydrogen: the stellar equivalent of a baby uttering its first words.
The circumstellar disk of AS 209 was found to have several gaps. And, in one of them, the radio telescope detected the distinctive radio wave of the storm that occurs when a planet is being created, gas that presumably envelops a world that is still under construction and that resembles Jupiter.
The calculation of the precise age of the planet will not be resolved soon, but it is likely to be very similar to that of its nascent star.. However, his youth is not the only thing that is attracting the attention of astronomers. It is also a bewildering distance from its star. Neptune, the farthest planet in our solar system, is about 4.5 billion kilometers from the Sun. This exoplanet is almost 30.6 billion kilometers from its own star.
This raises questions about our own corners.
The size of the debris disk that forged Earth and the other planets is not known. “Perhaps the disk was slightly larger than the orbit of Neptune and that is why Neptune is the farthest planetJohansen suggested. However, perhaps our core of matter to create planets was more similar to that of AS 209. If so, “we also cannot rule out that our solar system has a planet beyond Neptune”, added Johansen… perhaps it is that hypothetical Planet 9 that some astronomers suspect is surviving in a distant darkness.
In the coming days, the James Webb Space Telescope will determine the newborn planet’s mass and study its atmospheric chemistry. Furthermore, by painting a detailed portrait of one of the youngest worlds known to science, these observations will bring us ever closer to answering the main question, said Jaehan Bae, an astronomer at the University of Florida and an author of the study: “ Where we come from?”.