Binarity of a protostar affects the evolution of the disk and planets

Nearly half of all stars similar to our Sun are in binary or multiple systems¹, which may affect the evolution of the stars and their protoplanetary disks during their earliest stages. NGC 1333-IRAS2A is a young, Class 0, low-mass protostellar system located in the Perseus molecular cloud². It is known to drive two bipolar outflows that are almost perpendicular to each other on the sky^3,4 and is resolved into binary components, VLA1 and VLA2, through long wavelength continuum observations⁵. Here we report spatially and spectrally resolved observations of a range of molecular species. We compare these to detailed magnetohydrodynamic simulations: the comparisons show that inhomogeneous accretion onto the circumstellar disks occurs in episodic bursts, driving a wobbling jet. We conclude that binarity and multiplicity in general strongly affect the properties of the emerging stars, as well as the physical and chemical structures of the protoplanetary disks and therefore potentially any emerging planetary systems.

Natural separation of two primordial planetary reservoirs in an expanding solar protoplanetary disk

Meteorites display an isotopic composition dichotomy between noncarbonaceous (NC) and carbonaceous (CC) groups, indicating that planetesimal formation in the solar protoplanetary disk occurred in two distinct reservoirs. The prevailing view is that a rapidly formed Jupiter acted as a barrier between these reservoirs. We show a fundamental inconsistency in this model: If Jupiter is an efficient blocker of drifting pebbles, then the interior NC reservoir is depleted by radial drift within a few hundred thousand years. If Jupiter lets material pass it, then the two reservoirs will be mixed. Instead, we demonstrate that the arrival of the CC pebbles in the inner disk is delayed for several million years by the viscous expansion of the protoplanetary disk. Our results support the hypothesis that Jupiter formed in the outer disk (>10 astronomical units) and allowed a considerable amount of CC material to pass it and become accreted by the terrestrial planets.