Surprising Spiral Structure Spotted by ALMA

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered a totally unexpected spiral structure in the material around the old star R Sculptoris. This is the first time that such a structure, along with an outer spherical shell, has been found around a red giant star. It is also the first time that astronomers could get full three-dimensional information about such a spiral. The strange shape was probably created by a hidden companion star orbiting the red giant. This work is one of the first ALMA early science results to be published and it appears in the journal Nature this week.