Star formation begins when the densest regions in molecular clouds collapse under their own weight forming so called “young stellar objects” (YSOs), i.e. protostars surrounded by a gas and dust disc (known as “protostellar” or “protoplanetary” disc), expected to be the birth place of planets in this newly formed proto-exo-solar systems. The project ORBIT-D (Observing Binaries in Transition Discs) aims to study a special class of these discs that presents a cavity in the disc centre, the so called “transition discs”, that are believed to form due to the presence of an additional planetary/stellar companion to the primary star: i.e. a second protostar or a massive planet. Nevertheless, transition discs in which such a companion was detected are rare, questioning this hypothesis as a mechanism for the formation of such cavities.
In this context, by using analytical, numerical and observational techniques, the project ORBIT-D developed new diagnostics for the indirect detection of binary companions in transition discs, studying and modelling the perturbations that they produce in the disc.
The project produced tools and methods to identify hidden companions, quantify their effects on disc structure, and apply these results to actual astronomical observations. By bridging the gap between theoretical predictions and observational evidence, ORBIT-D contributes to more accurate assessments of disc evolution and planet formation.
The project’s results are particularly relevant for making full use of high-resolution data from modern radio and infrared light telescopes, upcoming facilities such as the Extremely Large Telescope (ELT) and future exo-planet detection missions. ORBIT-D thus addresses both the scientific challenge of understanding complex stellar and planetary systems and the strategic need for effective interpretation of rapidly expanding observational datasets.
