Sunspots

• Areas of highly concentrated magnetic flux on the photosphere

• Up to many times larger than the Earth

• Appear dark because they are much cooler than their surroundings (T=2000 K)

• Most are visible for just a few days (can exist for hours up to months)

• Usually found in pairs of opposite magnetic polarity (in and out of the sun)

• How they form, remain cool and stable, and then disappear is not entirely understood
 

This white light image of the photosphere taken with the NSF's GONG instrument in 2001 shows a number of sunspots
 

Next    Outline