1. Maria Pia Younger CDS 301 – Prof. Weigel
The Sun Spot Cycle
Maria Pia Younger CDS 301 – Prof. Weigel

2. What are sunspots?
Sunspots appear as dark spots on the surface of the Sun. They are created by strong magnetic field on the sun and are colder than the areas surround them. They typically last for several days, although very large ones may live for several weeks.
The sunspot number (SSN) is calculated by first counting the number of sunspot groups and then the number of individual sunspots.
Sunspots are magnetic regions on the sun, which magnetic field strength is thousand times stronger than the Earth’s magnetic field. Its magnitude at the Earth's surface ranges from 25 to 65 microtesla (V*s/1000m^2). Sunspots temperature can drop to 4,000 K (~ 3,700° C or 6,700° F). The sun’s magnetic field changes polarity approximately every 11 years.

3. “The "sunspot number" is then given by the sum of the number of individual sunspots and ten times the number of groups.” – NASA. Highest number: Month, Year: October, Mean number: 52.0 Month, Year: February,1758 and March,1896
Last Update
SSN: 74.7
Month, Year: August, 10, 2014.
Cycle: 11 years.

4. Source