Relative orbit of the GG Tau Ab and UX Tau B binaries. In both panels, orange symbols represent published astrometric datapoints whereas blue symbols indicate new adaptive optics or HST observations that are presented here for the first time. In 2012 and 2013 (orange and red symbols, respectively), the PIONIER observations of GG Tau Ab allowed two and three possible solutions, respectively. Based on the Keck observations, solutions “a” in both epochs are the most plausible ones.