Astronomers for the first time in history received an imagethe birth of a planet from a protoplanetary disk surrounding its native star, an orange dwarf located about 370 light years from Earth. The presence of an emerging planet near the star PDS 70 has been suspected for a long time, but scientists have only been able to confirm the presence of the world, called PDS 70b. Astronomers shared the results of observations on the pages of the journal Astronomy & Astrophysics.
Despite the fact that astronomers havea rather detailed model of planetary formation, confirming it in practice turned out to be a rather problematic task. We know that with the advent of new stars, a protoplanetary disk is formed around them, consisting of dust, gas and other matter. The process of planetary accretion (the formation of a new planet) begins with the collision and adhesion of particles of the above-described matter. “Walking” in the star’s orbit, accumulating mass and gravity, matter ultimately forms a planetary form.
Astronomers have previously found severalprotoplanetary disks and even noted characteristic spectral features indicating the orbital course of protoplanets inside these disks. However, in fact, scientists have not been able to capture the young planet, which is only just forming at the star, until this moment. The main difficulty was the distance. Exoplanets, as a rule, in such cases were too far away and too dim for them to be seen in optical telescopes. The brightness of the stars themselves simply overlapped their albedo. For the same reason, for example, we do not see other stars in the sky during the day. This does not allow the light of our sun.
Substantial research progressThe protoplanetary disk of the star PDS 70 was reached in 2012, when scientists from the Institute for Astronomy of the Max Planck Society and the European Southern Observatory decided to engage in a targeted search for a new planet around this star.
“We have long known that inside protoplanetary disksprotostars are undergoing processes of formation of new planets, but until that moment, the only thing that we managed to detect directly was just a few indirect hints, ”says astronomer Miriam Keppler from the Max Planck Institute for Astronomy.
“We saw the majority of potential planetary candidates as minor distortions or features against the background of protoplanetary disks.”
Scientists decided to choose a PDS star for observation70 at once for several reasons. Firstly, its protoplanetary disk is large enough - the radius is about 130 astronomical units (1 AU = distance from the Earth to the Sun; the same Kuiper belt is located at a distance of about 50 AU from the Sun). Secondly, since this is an orange dwarf star with a mass slightly less than the Sun and not very high luminosity, it was easier for astronomers to search for a probable planet located inside a protoplanetary disk.
Using the coronograph of a very large telescope, andAlso, a set of polarizing filters that allow you to block a certain type of light waves, scientists found a very large planet inside the protoplanetary disk of the PDS 70 star. All the data collected indicated that the planet is still gaining the mass it needs and taking matter from the disk.
Further analysis of the object showed that its massseveral times the mass of Jupiter, and its orbit lies about 22 astronomical units from the star, which is slightly further than Uranus is located from the Sun. A complete revolution around the PDS 70 star takes 120 Earth days on the planet. At the same time, scientists were able to find out the approximate temperature of the planet - about 1200 kelvin (927 degrees Celsius).
The young planet turned out to be hotter than any planetour solar system. For comparison, the temperature of Venus - the hottest planet in our system - is 737 degrees Kelvin (464 degrees Celsius). In addition, scientists suspect that the planet is covered in clouds that change the radiation coming from its core.
Scientists doubt its potentialhabitability, however, it is noted that the fact of direct observation of the still forming planetary body is more important, which gives astronomers a huge store of new knowledge.
“If we want to fully understand the process of planetary formation, we need to conduct direct observations of how new planets are born,” the scientists conclude.