Sunspots
- Galileo first noticed sunspots with his telescope
- showed dark spots right at surface of sun
- proved sun wasn’t perfect either
- led to acceptance of Copernican system
- very large spots can be seen with the naked eye
- Chinese astronomers reported some ~ 1000 AD
- much complex structure
- often in pairs
- N-polarity next to S-polarity
- energetic activity associated with high B-fields (video)
- most spectacular solar flares
- large heating and launching of particles into space
- always happen near large sunspots with large B-fields