The different classifications
[link to www.spaceweatherlive.com]
The delta classification
Let's digg a bit deeper into the magnetic delta class. This is the most interesting type of sunspot due to the high activity they can cause. With the following list you can determine whether a sunspot has a magnetic delta structure:

1.Delta groups are often very big and 90 percent of the sunspots have a reversed polarity with a high activity level, especially when big solar flares erupt. These have mostly a complex, unusual or broken view of the umbra.
2.Delta groups form by the are formed by the aggregation of sunspots with opposite polarity of various dipoles, which are linked to shared magnetic field lines rather than direct magnetic lines. All spots are located in the penumbral region.
3.Delta spots often last longer than one rotation of the Sun than other sunspots. However, new delta spots can be formed within the same area.
4.Delta sunspot groups usually do not separate, but rather die together.
5.Active delta groups emit strong H-alpha emissions. Sometimes filaments can come out of the group.