Astronomers at the US National Radio Astronomy Observatory have determined that disk mass and gravitational instability play a key role in planet formation.
How exactly planets are formed is one of the main questions in our field. However, there are some key mechanisms that, in our opinion, can speed up the process of planet formation. We first found direct kinematic evidence of gravitational instability in the Elias 2-27 system.
Teresa Paneke-Carreño, explorer
It was previously known that planets form in protoplanetary disks around young stars, but the necessary conditions for a planet to appear remained a mystery to scientists.
The authors of the new work observed the young star Elias 2-27: it is located 400 light-years from Earth in the constellation Ophiuchus. Based on data on the star’s gas velocity, the researchers calculated the mass of its protoplanetary disk.
In addition, they discovered gravitational instability in the Elias 2-27 system, arising from the fact that a significant part of the system’s mass falls on the disk matter.
Even during the early observations of Elias 2-27, scientists drew attention to the dusty disk of a spiral structure rotating around the star. The researchers decided that the spirals are the result of uneven density. Previously, such spiral arms were observed in galaxies such as the Milky Way, never before – around individual stars.
Based on the results of the new work, the authors argue that such instability, as well as vertical asymmetry in the protoplanetary disk and velocity disturbances, indicate the beginning of planetary formation.