Lagrange is a leading figure in direct-imaging exoplanet science, using the VLT/SPHERE extreme-adaptive-optics coronagraph (which she helped design and exploit) to detect and characterize young giant planets around nearby stars, most notably the beta Pictoris planetary system, and to study debris-disk and planet-formation signatures such as non-common-path aberration correction algorithms for next-generation direct-imaging instruments.

Owen works on the theory and observational consequences of protoplanetary disk evolution, photoevaporation and exoplanet demographics, explaining features such as the observed radius gap in close-in exoplanets.