Astronomers for the first time in the history of the image of the birth of planets from a protoplanetary disc surrounding their home star, an orange dwarf star located about 370 light years from Earth. About the presence of emerging planets near the star PDS 70 suspected for a long time, but confirm the presence of the world, called PDS 70b, the scientists were able only now. The results of observation, astronomers have shared in the pages of the journal Astronomy & Astrophysics.
Despite the fact that astronomers have a rather detailed model of planetary formation, to confirm it in practice proved to be quite problematic. We know that with the emergence of new stars around them, a protoplanetary disk composed of dust, gas and other matter. The process of planetary accretion (formation of a new planet) starts with collision and coalescence of particles of the above matter. “Walking” along the orbit of the star, gaining mass and gravity, matter will eventually form a planetary form.
Previously, astronomers have found several protoplanetary disks and even noted typical spectral features indicating the course of protoplanets orbiting within these disks. In fact, however, to capture young planet, still forming stars, scientists to this point have failed. The main difficulty was in the distance. Exoplanets, as a rule, in such cases were too far and was too dim to be seen in optical telescopes. The brightness of the stars themselves just blocked their albedo. For the same reason we don’t see the other stars in the sky. This does not allow the light from our Sun.
Significant progress in the study of the protoplanetary disk of the star PDS 70 was achieved in 2012, when scientists from the Institute of astronomy of the max Planck society and the European southern Observatory decided to do a targeted search of a new planet around that star.
“We know what’s inside protoplanetary disks protostars, there are processes of formation of new planets, but up to this point the only thing we were able to detect directly, so it’s only a few indirect hints,” says astronomer Miriam Keppler from the Institute of astronomy of max Planck.
“The majority of potential planetary candidates see us as minor distortions or features in the background of protoplanetary disks”.
Scientists decided to choose for observation a star PDS 70 for several reasons. First, its protoplanetary disk is sufficiently large – a radius of 130 astronomical units (1 a.e. = distance from Earth to the Sun; the same Kuiper belt is from the Sun at a distance of about 50.e.). Secondly, since we are talking about the star-class orange dwarf, with a mass slightly less Sunny and a very high luminosity, astronomers it easier to search the probable planets inside of the protoplanetary disk.
Using the coronagraph of Very large telescope, and a set of polarizing filters to block specific wavelengths of light, scientists found inside the protoplanetary disk of the star PDS 70 is a very big planet. All the collected data pointed to the fact that the planet is still gaining weight she needs and takes the matter out of the disk.
Further analysis of the object showed that its mass is several times the mass of Jupiter, and its orbit about 22 astronomical units from the star, which is slightly farther than Uranus is from the Sun. Performance of the full revolution around the star PDS 70 is a planet 120 earth days. Meanwhile, the scientists were able to figure out the approximate temperature of the planet is about 1200 K (927 degrees Celsius).
The young planet was hot any planet in our Solar system. For comparison, the temperature of Venus – the hottest planet in our system is 737 Kelvin (464 degrees Celsius). In addition, scientists suspect that the planet is covered with clouds, which change the radiation coming from its core.
Scientists are very aware of the potential of its habitability, however, point out that more important is the fact of direct observation of still emerging planetary body that gives astronomers a huge Luggage of new knowledge.
“If we want to fully understand the process of planetary formation, we need to conduct direct observations of the birth of a new planet,” the researchers summarize.
Astronomers for the first time directly see the process of the birth of the planet
Nikolai Khizhnyak