Astronomers using the telescope VLT has got the most precise to date image of the protoplanetary disk of the young star AB Auriga, which allowed to reveal the location of massive proto-planet, actively growing through the accretion of matter from the disk. Article published in the journal Astronomy & Astrophysics, briefly about work it is reported on the website of the European southern Observatory.
It is believed that forming planets in protoplanetary disk takes millions of years and is manifested in different observed structures, such as the asymmetry of the disk, clumps, rings, or spirals, resulting from gravitational and hydrodynamic processes. The simulation shows that at an early stage of formation of the planet, the process of accretion of matter onto the core generates internal and external helical structure due to Lindblad resonancescaused by interactions of the disk with the planet. Although this phenomenon has good theoretical justification, it is confirmed by only a very small amount of data observations, which are not always convincing.
System AB Auriga is a very curious and important for astronomers the object from the point of view of the study of the mechanisms leading to the formation of giant planets. This is a young (2-4 million years) dwarf star, non – star Herbig Ae and located 520 light years from the Sun. It has a huge (the size of a few hundred astronomical units) of the protoplanetary disk of gas and dust, observations of which have been conducted for more than ten years in the optical, near-infrared and millimeter ranges. They have allowed two helical gas branches in the inner part of the disk that can be created with two planets located in the 30 and 60-80 astronomical units from the star, and void, which may also indicate formed in the disk body.
A team of astronomers led by Anthony Boccaletti (Anthony Boccaletti) from Paris Observatory has set the task to obtain new detailed images of AB Auriga system, for this purpose, they used the receiver SPHEREmounted on one of the telescopes of the VLT complex in Chile. He is able to obtain direct images of exoplanets by blocking light from the parent star and image the circumstellar and protoplanetary disks with a good resolution. Polarimetric and spectroscopic observations of AB Auriga was held in December 2019 and January 2020.
The result of the observations was to obtain the clearest images of the protoplanetary disk of AB Auriga system today. Scientists were able to confirm the presence of the spiral branches, and register the radiation from the inner part of the disk, were also discovered curved structure that represents a point of connection of two spiral branches, one of which curl inward and the second outward. It is assumed that at this point is a protoplanet with a mass from 4 to 13 Jupiter masses, which is growing rapidly due to the accretion of matter from the disk. Further observation of the system should help to estimate more accurately the parameters of exoplanets and growing to understand the dynamics of gas flows in the disk.
Earlier we talked about how astronomers first got direct the nascent planet, saw young stars circumstellar disks, and found the protoplanetary disk from the newly born stars.