Two decades ago scientists determined that the outer five percent of our Sun spins at a slower rate than the rest of its layer. Now, in a breakthrough study, astronomers from the University of Hawaii Institute for Astronomy, Brazil, and Stanford University, have discovered a physical mechanism that plays a crucial role in slowing down the outer layers of the Sun.
Just a gentle torque is slowing it down, but over the Sun’s five billion year lifetime it has had a very noticeable influence on its outer 35,000km. The Sun rotates on its axis is about once per month, although the rotation cannot be compared to the one experienced on our solid Earth, or on a spinning disc, as the rate of the rotation depends on the solar latitude and the distance from the star's centre. The change in the rotation rate at the surface of the Sun affects its large-scale solar magnetic field, and scientists are currently working to understand how this solar magnetism, extending not only into the corona, but to Earth's environment as well, will be impacted by a discovered brake effect.
The research describes the mechanism, named 'photon-braking effect' in detail and explains how it should work in most stars. No cause for panic - the Sun won’t stop spinning completely anytime soon!
Source reference: https://watchers.news/2016/12/20/photon-braking-effect//
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