SPIRou observations reveal magnetic polarity reversal and accretion in DO Tauri

Star system: DO Tauri | Distance from the Sun: 452 light years

DO Tauri is a classical T Tauri star, a type of young star still surrounded by a disk of gas and dust. Researchers monitored DO Tau using the SPIRou spectropolarimeter at the Canada-France-Hawaii Telescope between 2020 and 2025, aiming to understand its magnetic activity and accretion processes.

The study detected strong, variable magnetic fields in DO Tau, including a rare magnetic polarity reversal—meaning the star's large-scale magnetic field flipped direction. This is the first time such a reversal has been reported in a T Tauri star. The observations also revealed a compact magnetospheric gap and a high rate of material accreting from the disk onto the star, with the inner disk being warped by the tilted magnetic field.

Radial velocity changes in the data suggest either a close-in planet or a dense structure in the inner disk, orbiting every 21 days. These findings help scientists better understand how young stars interact with their disks and how their magnetic fields evolve over time.

Key findings

 
DO Tau's magnetic field showed a rare polarity reversal during the observation period.
 
Strong accretion from the disk to the star was detected, with the inner disk warped by the magnetic field.
 
A compact magnetospheric gap was observed, extending to about 1.6 times the star's radius.
 
Radial velocity variations suggest a close-in planet or disk structure with a 21-day orbit.
 
These results provide new insights into the evolution of magnetic fields and accretion in young stars.

Scientific study

Monitoring the magnetospheric accretion of the classical T Tauri star DO Tau with SPIRou (external link)