Acoustic waves reveal that some stars spin faster at the equator than at the poles
Spinning around: the green arrows represent rotation speed in the stellar convection zone. Differential rotation is inferred from the oscillatory motions of the star seen as orange/blue shades on the right side of the figure. (Courtesy: MPI for Solar System Research/MarkGarlick.com) An international team of astronomers has observed latitude-varying rotation in the outer layers of 13 Sun-like stars and shown in great detail that the Sun is not alone in displaying this curious behaviour. Othman Benomar at New York University, Abu Dhabi and his colleagues made the discovery by measuring distinctive patterns of acoustic oscillations in the stars. Their discovery could help to advance our understanding of the elusive mechanisms which play out deep within the Sun and other stars. By observing the movements of sunspots across the Sun’s surface, astronomers have known for some time that our host star’s equator rotates 30% faster than its poles – a phenomenon known as “differenti...