Free Astronomy Magazine May-June 2019

40 MAY-JUNE 2019 SPACE CHRONICLES sudden increase of luminosity due to a bursting torrent of material flow- ing from the disk to the star. These outbursts last only on the order of 100 years, therefore the chance to observe a burst is rather rare. However, since young stars with a wide range of ages experi- ence FU Ori bursts, astronomers ex- pect to be able to trace the chemical composition of ice throughout the evolution of young stars. S chematic illus- tration of the composition of protoplanetary disks in normal state and out- burst phase. V883 Ori is experienc- ing an FU Orionis outburst and the increase in disk temperature pushes the snow line outward, causing various molecules con- tained in ice to be released into gas. [National Astro- nomical Observa- tory of Japan] made from solid material, the chem- ical composition of solids in disks is of special importance. An outburst is a unique chance to investigate fresh sublimates, and thus the composi- tion of solids,” says Yuri Aikawa at the University of Tokyo, a member of the research team. V883 Ori is a young star located at 1300 light-years away from the Earth. This star is experiencing a so- called FU Orionis type outburst, a Probing the chem- ical composition of ice in pro to- planetary disks is directly related to probing the origin of organic mole- cules in comets, and the origin of the building blocks of life. Thanks to ALMA’s sharp vision and the enlarged snow line due to the flare-up of the star, the astrono- mers obtained the spatial distribution of methanol and acetaldehyde. The distribution of these molecules has a ring-like structure with a radius of 60 au, which is twice the size of Nep- tune’s orbit. The researchers assume that inside of this ring the molecules are invisi- ble because they are obscured by thick dusty material, and are invisi- ble outside of this radius because they are frozen in ice. “Since rocky and icy planets are !