The motion of Beta Pictoris b

For the first time, astronomers have been able to directly follow the motion of an exoplanet as it moves to the other side of its host star. The planet has the smallest orbit so far of all directly imaged exoplanets, lying as close to its host star as Saturn is to the Sun.

This sequence shows composite images of the disc around Beta Pictoris, as well as the position of the planet as seen by the NACO instrument on ESO’s Very Large Telescope in 2003 and in autumn 2009. The possible orbit of the planet is also indicated, with an angle that has been exaggerated.