10-4 Sunspots Flashcards
1
Q
sunspots
A
sunspots are cooler regions of photosphere due to magnetic activity about 10,000 km across. they serve as markers to study rotation and sometimes form groups lasting for hours to months
2
Q
the sunspot cycle
A
the number of sunspots on the sun varies with a period of about 11 years
3
Q
the sun’s rotation
A
by observing sunspots, Galileo found that the sun rotates once every four weeks (25 days near equator, 35 days near poles)
