Free Astronomy Magazine November-December 2019

35 NOVEMBER-DECEMBER 2019 SPACE CHRONICLES T his picture shows Barnard 59, part of a vast dark cloud of inter- stellar dust called the Pipe Nebula. This new and very detailed image of what is known as a dark nebula was cap- tured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observa- tory. [ESO] T his artis- tic ani- mation shows two circumstellar disk orbiting each other and accret- ing gas and dust for their surrounding cloud. [ESO/L. Calçada] mass is transferred to the individual circumstellar disks in beautiful twirling loops, which is what the new ALMA image showed. The data analysis also revealed that the less- massive but brighter circumstellar disk — the one in the lower part of the image — accretes more material. In the second stage, the stars accrete mass from their circumstellar disks. “We expect this two-level accretion process to drive the dynamics of the binary system during its mass accre- tion phase,” adds Alves. “While the good agreement of these observa- tions with theory is already very promising, we will need to study more young binary systems in detail to better understand how multiple stars form.” they were born. This provides impor- tant constraints for current models of star formation.” The baby stars accrete mass from the bigger disk in two stages. The first stage is when ! in our Solar System and the separation between them is 28 times the dis- tance between the Sun and the Earth,” notes Alves. The two circum- stellar disks are sur- rounded by a bigger disk with a total mass of about 80 Jupiter masses, which displays a complex network of dust struc- tures distributed in spiral shapes – the pretzel loops. “This is a really im- portant result,” stresses Paola Caselli, managing director at MPE, head of the Centre of Astrochem- ical Studies and co-author of the study. “We have finally imaged the complex structure of young binary stars with their feeding filaments connecting them to the disk in which