Astronomers directly observe protoplanetary disk rotation for first time

Tuesday 02 - 13:53

By: Dakir Madiha

Astronomers directly observe protoplanetary disk rotation for first time

For the first time, astronomers have directly observed the rotation of a protoplanetary disk, capturing a sequence of images over four years that reveals the motion of gas and dust surrounding the young star AB Aurigae. The observations provide an unprecedented view of the environment where planets form and evolve.

The research, published on June 1, 2026, in Astronomy & Astrophysics, was conducted by scientists from the CNRS and the University of Bordeaux. Using the SPHERE instrument mounted on the European Southern Observatory's Very Large Telescope in Chile, the team tracked emissions from dust grains within the disk around AB Aurigae, a young star located about 520 light-years from Earth in the constellation Auriga.

By blocking the intense light emitted by the central star, SPHERE allowed researchers to capture detailed images of the surrounding disk through three observation campaigns carried out over four years. The resulting image sequence clearly shows the disk rotating around the star. Previous studies inferred such motion by measuring gas velocities, but this marks the first time that the movement has been directly mapped through dust emissions.

While the overall rotation follows the behavior predicted by established physical laws, scientists detected unusual activity in regions close to the star. The observations revealed a bright structure associated with accretion zones, where gas and dust accumulate and fall onto a forming object. Researchers say such features are closely linked to the creation of giant gas planets.

The images also uncovered faint shadows moving rapidly across the surface of the disk. These shadows appear to be cast by structures that cannot yet be directly observed. Scientists suggest they may be protoplanets or dense clumps of dust orbiting near the star and influencing the disk's dynamics.

AB Aurigae has long served as a key laboratory for studying planetary formation. In 2020, observations with the same SPHERE instrument revealed spiral structures and a warped region within the disk, indicating a likely site of planet formation. In September 2025, another research team detected hydrogen emissions from the protoplanet AB Aurigae b using the Very Large Telescope, providing direct evidence that the young planet was actively accreting material while still embedded within surrounding dust.

Researchers noted that the newly observed structures are more complex than current theoretical models predict. They say additional observations will be needed to directly identify the properties of the protoplanets or dense dust concentrations responsible for the unusual motions detected within the disk, potentially improving scientific understanding of how planetary systems emerge.