Binarity of stars seems to be rather the rule than the exception. As many as 80% of pre-main sequence stars may be binaries. To understand planet formation, it is then of prime importance to study the mass distribution and evolution of circumstellar matter around young binary systems.

 

 

Top: Interferometer observations in the 13CO(2-1) line of the GG Tauri young binary system. It consists of two pre-main sequence stars gravitationally bound (projected separation 38 AU*) ; its total mass is 1.2 solar masses. In false color, the image of the thermal emission of dust at 1.3 mm reveals a ring-like structure surrounding the binary. The inner material has been cleared by tidal interactions related to binarity.

(* One Astronomical Unit (AU) is the mean distance between the Sun and the Earth, roughly 150 million kilometers.)