Context : With an orbital distance comparable to that of Saturn in the solar system , \beta Pictoris b is the closest ( semi-major axis \simeq 9 au ) exoplanet that has been imaged to orbit a star .
Thus it offers unique opportunities for detailed studies of its orbital , physical , and atmospheric properties , and of disk-planet interactions .
With the exception of the discovery observations in 2003 with NaCo at the Very Large Telescope ( VLT ) , all following astrometric measurements relative to \beta Pictoris have been obtained in the southwestern part of the orbit , which severely limits the determination of the planet ’ s orbital parameters .

Aims : We aimed at further constraining \beta Pictoris b orbital properties using more data , and , in particular , data taken in the northeastern part of the orbit .

Methods : We used SPHERE at the VLT to precisely monitor the orbital motion of beta \beta Pictoris b since first light of the instrument in 2014 .

Results : We were able to monitor the planet until November 2016 , when its angular separation became too small ( 125 mas , i.e. , 1.6 au ) and prevented further detection .
We redetected \beta Pictoris b on the northeast side of the disk at a separation of 139 mas and a PA of 30 ^ { \circ } in September 2018 .
The planetary orbit is now well constrained .
With a semi-major axis ( sma ) of a = 9.0 \pm 0.5 au ( 1 \sigma ) , it definitely excludes previously reported possible long orbital periods , and excludes \beta Pictoris b as the origin of photometric variations that took place in 1981 .
We also refine the eccentricity and inclination of the planet .
From an instrumental point of view , these data demonstrate that it is possible to detect , if they exist , young massive Jupiters that orbit at less than 2 au from a star that is 20 pc away .

Conclusions :