In November 2010, the dwarf planet Eris passed in front of a faint star in the Cetus constellation. The observations of this occultation with, among others, the Liège robotic telescope TRAPPIST gave unexpected and important results.

ULiège is the first francophone Belgian university to equip itself with a robotic telescope. Responding to the effervescent name of TRAPPIST, it will scan the starry skies of Chile in the search for exoplanets and comets.