An international team of astronomers has discovered that protoplanetary discs around
young stars may not be perfectly flat, but slightly ‘warped’. These deformations, as shown by observations with the ALMA radio telescope, can explain the differences in the inclinations of the orbits of the planets in the Solar System.
The study was conducted as part of the exoALMA project led by Andrew Winter of
Queen Mary University of London. Scientists studied 15 protoplanetary disks in the Cygnus OB2 star cluster, located 4,600 light-years from Earth. Analysis of carbon monoxide molecule emissions showed that the inclination of gas rings within the discs can vary by 0.5–2 degrees.
Modelling confirmed that such small ‘bends’ can form spiral patterns and temperature fluctuations in the gas, as well as influence the future location of planetary orbits. According to the scientists, it is precisely these distortions in the structure of the discs that could be the reason why the inclinations of the orbits of Earth, Mars and Jupiter differ.
“Knowing that discs are rarely perfectly flat allows us to take a fresh look at the processes of star and planet formation,” Winter noted. The results of the study are published in the journal. The Astrophysical Journal Letters.
Astronomers plan to continue their observations using the James Webb Observatory to determine how common ‘warped’ protoplanetary discs are in our galaxy.
