How are sunspots formed?
Why are sunspots created? What is the reason behind them?
Sunspots appear darker than the rest of the surface of the Sun because they are cooler. The center of a sunspot (called the umbra) has a temperature of around 3700 Kelvin while the surrounding photosphere has a temperature of 5800 Kelvin. Sunspots are also regions of strong magnetic fields (thousands times stronger than the Earth's field) and usually occur in pairs (one being a north pole and the other being a south pole).
Why certain regions on the Sun's surface are cooler than others is not well understood. One theory is that the strong magnetic fields in these spots inhibit convection below the surface. (Convection is the transfer of heat from a hot location to a cold one.)
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
- What's that dark spot on the Sun?
- What is the solar cycle?
- How many sunspots can the Sun have at once?
- How do we know that sunspots are associated with the Sun's magnetic field?
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist
This page has been accessed 24219 times since April 25, 2006.
Last modified: April 25, 2006 4:47:58 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)