Astronomers found the planet, contrary to the laws of planetary formation

According to a new study, one giant and distant world that was once described as "the planet that shouldn't be where she is" seems to have really formed, not where one would expect, and not from the outer material, which would have to be a part of and thanks to which are born almost all the known world.

Anomalous object, dubbed HD 106906b is a very young planet, located about 300 light years from Earth in the constellation of the southern Cross. For the first time a planet was discovered in 2013. Makes it unique is that, at what distance from its star it is, about 650 astronomical units, or 650 times farther than the distance from the Earth to the Sun. This unique feature HD 106906b gives her the title of planet with the most distant orbit around a single sun-like star. For a complete revolution around its sun the planet should be about 1500 years old.

However, the most interesting feature HD 106906b relevant even with its huge orbit, and that planet is far beyond the outer reaches of outer planetary material (gas and dust, that is, the matter from which the planets formed), collected around the star HD 106906. In our case, the protoplanetary disk is about 10 times closer to the star than the planet itself HD 106906b, which in turn, causes astronomers to think about how it could in this case be formed.

HD 106906 System (black circle marked with the star itself) and its protoplanetary disk (bottom left) and planet HD 106906b (top right)

"Our current theories of planetary formation do not take into account the possibility of the location of a planet beyond the outer limits of the planetary disk" — explains astrophysicist smadar Naoz from the University of California in Los Angeles.

Naos and her team are now developing a computer model that could track the orbital path of the planet HD 106906b.

Since the first discovery of the planet, scientists are trying to explain how she was so distant from its star HD 106906, as the vast majority of exoplanets are usually, located inside the planetary disk. For example, in our Solar system all the planets are within the boundaries of the Kuiper belt, beyond the orbit of Neptune and consists of dwarf planets, and other small space objects, as well as of matter, remaining after the formation of the planets.

Previous studies of the planet HD 106906b pointed to the fact that it could be formed within the protoplanetary disk before gravity pushed her actually outside of their system, however, according to Nos and her team, the scenario was different.

According to the established in the Carnegie Institute computer model "algorithm supertastic collisions in the Kuiper belt and planetary disks" (SMACK), the planet is likely to have really formed beyond the outer limits of its protoplanetary disk. A computer model, which introduced a known about the HD 106906 system the data showed that there were planet HD 106906b within the boundaries of the protoplanetary disk, it would have affected the whole structure of this disk.

For scientists remains unknown whether the HD 106906 system the other planets, however, the computer model showed that the elliptical form of the protoplanetary disk systems indicates only the connection to the planet HD 106906b.

"With the help of computer simulations we were able to recreate the well-known form of drive system HD 106906 without the addition of other planets. However, according to earlier assumptions, the system must be other planets to disk acquired this form" — says researcher Eric Neswold from the Carnegie institution.

As mentioned above, the model also shows that the planet HD 106906b most likely formed outside of the disk. If the planet initially formed within the boundary of the disk, after its gravitational garbage she'd pulled a part of the disk and the last would have a different form.

At the moment, scientists still can not accurately tell exactly how of gas and dust system, which usually formed the majority of other planets in other systems, there was the planet HD 106906b, and yet scientists have managed at least a little, but narrow history of its origin. If in the future we will be able to find similar in nature to HD 106906b planet, computer model SMACK will be able to tell more about how such planets can form.

"Other protoplanetary disks is also likely to have its shape under the gravitational influences that appeared on their giant planets belonging to this system", — says Nesvold. "My computer model could help in the reconstruction and visualization of those features which led to the different forms of protoplanetary disks. In the future it will help us to better understand the processes of evolution of planetary systems".