Horstman and collaborators go hunting for exomoons in “RV measurements of directly imaged brown dwarf GQ Lup B to search for exo-satellites” and get interesting upper limits - we’re not down to the mass ratio of the Galilean satellites (yet!) #astrodon 🔭🪐

A graph of semi-major axis distance from GQ Lup B versus mass ratio between planet and possible moon. The measured limit is about 100 times higher than for the Galilean moons.
Matthew Kenworthy @kenworthy