File:Sun fromsoho big.jpg

Summary

The sun with enormous, intensely bright, active regions, recorded by the SOHO Spacecraft's Extreme ultraviolet Imaging Telescope.

Explanation: Astronomers recently witnessed an astounding, large scale solar event as the Sun's north and south magnetic poles changed places! But, this complete solar magnetic field flip was actually anticipated. It occurs every 11 years during the maximum of the solar activity cycle. Plagues of sun spots, flaring active regions, and huge prominences are also hard-to-miss signs that the solar maximum is here. On February 12, the sungazing SOHO spacecraft captured this dramatic image of a magnificent prominence above the Sun's limb. Seen at the lower right, streams of relatively cool dense plasma were lofted along looping magnetic field lines extending outward about 30 times the diameter of planet Earth. Far above the limb at the upper right, a disconnected ghostly arc surrounds a dark cavity with bright central emission. These features are telltale signs of a coronal mass ejection -- yet another violent expulsion of material from the active Sun. Enormous, intensely bright active regions also mottle the solar surface in this image, recorded in the light of energetic Helium atoms by SOHO's Extreme ultraviolet Imaging Telescope.

Copyright status

NASA Website - public domain

Source

http://antwrp.gsfc.nasa.gov/apod/ap010301.html