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To capture this image, the Very Large Telescope researchers carefully filtered the light from the central star. The PDS 70b is visible at the bottom left and the PDS 70c at the top right.
Credit: ESO and S. Haffert (Leiden Observatory)
When the stars are young, they are surrounded by large circles of flattened material. Astronomers call these characteristics "protoplanetary disks" because it is their dust and gases that accumulate in the balls that eventually become planets. Researchers have long suspected that "protoplanets" – half-cooked worlds in these discs – could dig large gaps in the seas of soft materials that telescopes might see.
Now this theory seems confirmed, with two planets discovered in the gaps of a disk around PDS 70, a small star in the constellation Centaurus, located 370 light-years from Earth.
PDS 70 is a relatively new star in our galaxy. It was formed about 6 million years ago. (For comparison, our sun is about 4.5 billion years old.) And the extraterrestrial star is still surrounded by a disc that astronomers can spot with the help of telescopes .
This disc has a great fault, a place devoid of dust and gas, visible by the most advanced telescopes of humanity, such as ALMA, a network of radio telescopes in the Atacama desert and the Hubble Space Telescope. The PDS 70's disk extends 3.1 billion kilometers from the star (a little closer to the star than the one where Uranus revolves around the sun) to 6.1 billion kilometers , or further from the star than the average distance of Pluto. of the sun. [9 Most Intriguing Earth-Like Planets]
In July 2018, the very large telescope (VLT) of the European Southern Observatory spotted an immense planet, between four and 17 times the mass of Jupiter, revolving around the PDS 70 near the inner edge of this space. Astronomers have named this planet PDS 70b. In a new article published Monday, June 3 in the journal Nature Astronomy, scientists have revealed that there is a second planet in this space.
The new planet, PDS 70c, has a mass between 1 and 10 times greater than that of Jupiter. This world orbits closer to the outer edge of the gap, at a distance similar to that of Neptune (5.3 billion km). The PDS 70c orbits its star once for two orbits of its largest internal twin.
"We were very surprised when we found the second planet," said Sebastiaan Haffert, an astronomer at the Leiden Observatory in the Netherlands and senior author of the newspaper.
None of this goes to the level of evidence that protoplanetary disk holes like this one abound with young planets, the researchers wrote. But the results are suggestive.
"With equipment like ALMA, Hubble or large optical telescopes on the ground … we see discs with rings and empty spaces.The open question is, are there any planets out there?" this case, the answer is yes, "Julien Girard, astronomer at the Institute of Space Telescope Sciences in Baltimore and author of the paper, said the statement.
Locating exoplanets in such spaces is a challenge because, to be visible, the disc must have its flat face to the Earth, not its edge. But astronomers generally discover exoplanets indirectly by watching them pass in front of their stars. A planet orbiting a disk that faces the Earth will never pass between Earth and the star; such a world must be directly imaged. And while thousands of exoplanets have been discovered by the indirect method, direct detection is rare.
This is only the second multiplanet system ever imaged directly, the researchers said. And the two planets are part of a little over a dozen exoplanets never spotted directly.
The researchers hope to form telescopes other than the VLT on planets to learn more about them and to deepen scientists' understanding of how young planets form and are shaped by protoplanetary disks.
Originally published on Science live.
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