Scientists have reproduced in the laboratory the formation of planets around stars

© Illustration RIA Novosti . Alina Planinformation planets around starsScientists have reproduced in the laboratory the formation of planets around stars© Illustration RIA Novosti . Alina Polyanina

An international team of astrophysicists with the participation of employees of the National research nuclear University «MEPhI» conducted laboratory simulations of the increment of the mass of a celestial body by the gravitational attraction of matter from the surrounding space (accretion). The study is published in the journal Science Advances.

The study of accretion gives information on the exchange of mass, energy, and the mutual position between the «collection» object and its environment. It is thanks to this process formed planetary systems around stars. Often this occurs in the formation of young stars and in binary systems, where, for example, the role the recipient plays a matter black hole, a «donor» is often a neutron star.

The surrounding material (e-plasma, a «gas» of individual ions and electrons) and a young star associated with the lines of magnetic field, which affects particles in the composition of the plasma, changing their trajectory and directing to the star at supersonic speeds. Clash heats matter to several million degrees, there is excess UV and x-ray radiation in the so-called accretion column, which results in change of physical and chemical structure around a young star.

There are many limitations associated with monitoring and modeling of processes in astrophysics. For example, if the «live» stargazing and measuring various parameters can cause a discrepancy in respect of the same characteristics. Therefore, large-scale laboratory experiments help to study the processes of accretion.

In held with the participation of employees of the NRNU MEPhI research has created a new experimental platform, providing uniformity of the external magnetic field for the maximum approximation to astrophysical events. The results obtained using the laboratory approach and the use of the new platform, provide the first direct evidence for the formation of a dense shell of ionized plasma, covering the Central region of the inflow of the substance.

The researchers showed that the substance after the collision, objects can be thrown out and re-focus the magnetic field in the direction of the incoming flow. The formation of plasma sheath surrounding the disturbed core, can lead to reduction of yield of x-rays. This finding explains the possible cause of the mismatch measurements for the accretion of matter according to optical and x-ray observations.

«Our results emphasize the need for proper registration of the radiation absorption in the plasma for a proper modeling of the accretion processes in young stars. We have developed a laboratory platform also opens research on a number of other issues. For example, changing the orientation of the flow relative to the magnetic field, it is possible to explore alternative channels of accretion» — says one of the authors of the article, with the Institute for Laser and plasma technologies, national research nuclear University MEPhI Evgeny Filippov.