Sunspots are actually magnetic phenomenon on the sun that have been admired for thousands of years. Thank to sophisticated instruments that can measure the strength of solar magnetic fields from a distance of 93 million miles, we can map out what sunspot magnetic fields look like if we could see them with our eyes. The highest field strength of 3000 Gauss (red) occurs in the central umbra. 500 Gauss (blue) are measured in the outer penumbra. Arrows indicate the direction of the horizontal component of the magnetic field. The white contours show the outer edges of umbra and penumbra.
Posted on: Tue, 18 Jun 2013 01:03:18 +0000