News Physics

Shaping up the sun

The most accurate measurements yet account for magnetic activity that gives the star a more oval appearance.

By Ron Cowen

- More than 2 years ago

With its turbulent structure, tangled magnetic fields and a propensity to expel billion-ton clouds of charged particles, the sun makes it difficult to measure its exact shape.

Now researchers using a NASA spacecraft called RHESSI, the Reuven Ramaty High Energy Solar Spectroscopic Imager, have measured with unprecedented accuracy just how out-of-round the sun is.