Based on the speed of the star's rotation measured by the discoverers, and confirmed by this team, the astronomers believe that the star was originally part of a binary system. (carnegiescience.edu)
For the jets in the nebulae to form, the spherical AGB stars have to somehow become non-spherical and Blackman says that astronomers believe this occurs because AGB stars are not single stars but part of a binary system. (sciencedaily.com)
Frank Verbunt of Utrecht University, the Netherlands, believes the riddle may be solved by assuming that the progenitor star was part of a binary system. (sciencemag.org)