Thanks to Atacama Large Millimeter / submillimeter Array (ALMA), The astronomy team was watching for the first time circular disk, the ring of dust and gas that surrounds some planets and who, astronomers believe, control the formation of planets and create a complete system of months like the one around Jupiter.
This young star system, known as PDS 70, is about 370 light years from Earth. Recently, the presence of two massive planets similar to Jupiter, which circulates around the stars, has recently been confirmed. This discovery was made by a very large telescope (VLT) European Organization for Southern Hemisphere Surveying (ESO), which previously discovered the warm glow naturally emitted by gaseous hydrogen. increase in the direction of the planet.
The new ALMA observations show weak radio waves emitting small particles of dust around the star (about a tenth of a millimeter in diameter).
ALMA data, combined with VLT optical and infrared observations, provide a convincing proof that the dust bin is capable of forming multiple months surrounds the largest outdoor planet known in the system.
"For the first time, we see convincing evidence of a circular disk that is the basis of many current planetary formation theory," says Andrea Isella, astronomer from Rice University (Houston, Texas) and the author of the article published in The Astrophysical. Journal Letters.
"By comparing our observations with infrared and optical high resolution images, we can see that the strange concentration of small particles of dust is actually a circular disk dust, and this is the first time that this phenomenon is so obvious," he explains. ISEAL. According to researchers, this is the first time that the planet is clearly revealed in three types of light (infrared, optical and radio).
Unlike the Saturn's icy rings, which were probably formed after collisions of bodies similar to comets and rocky bodies, relatively recently in the history of our solar system, circular disks are the remains of planetary formation processes.
ALMA observations revealed two clear differences between the two newly discovered planets. The nearest center of the two, PDS 70 b, which is more or less distant from its star as the Sun Uranus, has a trace of dust behind it. "We still do not know what this is and what consequences it has for this planetary system," says Isella. "It is only certain that it is far enough away from the planet to be an independent object."
The other planet, the PDS 70c, is in exactly the same place as the location of the dust detecting ALMA data. As this planet is so bright in infrared and hydrogen belts, astronomers are convincing in explaining that there is already a planet in the orbit and that the gas surrounding it continues to move to its surface in the final growth. teenager.
This farthest planet is around 5.300 million kilometers Host stars, a distance similar to that shared by Neptune from our Sun Astronomers calculate to have between 1 and 10 times the mass of Jupiter. "If we have a mass closer to 10 masses of Jupiter, it is quite possible that this planet has lunar planetary scales in the process of forming around it," says Isella.
Alma's observations have also contributed to another important element.
Study of planetary systems is considerably more difficult with optical telescopes. Indeed, because the stars are much brighter than the planets, it is difficult to filter their brightness. It would be a bit like revealing the fireflies next to the lantern that blinds us. With ALMA, this problem does not happen because the stars emit very little light in millimeter and submilimeter wavelengths.
"This means that we can look at this system again at different times and simply map the orbit of the planet and the concentration of dust in the system, "concludes Isella. "That way, we will have unique information on the orbital properties of solar systems in their early stages of development."