News Astronomy

The sun shrinks a teensy bit when it’s feeling active

Its radius decreases by 1 or 2 kilometers during periods of high solar activity

Sun

SOLAR SHRINKAGE  The radius of the sun gets a smidge smaller during periods when the sun is most active, a new study reports.

Solar Dynamics Observatory/NASA

By Emily Conover

- More than 2 years ago

How big is the sun? Well, that depends on when you’re measuring.

The sun slightly shrinks and expands as it goes through a solar cycle, a roughly 11-year period of high and low magnetic activity, a new study finds.