Name: ______________________
Date: ______________________
Sunspot Classification
People like patterns. When we see a pattern, we can generally figure out what comes next. Scientists have been classifying sunspots for many years and in many ways. One method of classification, the Zürich Method of Sunspot Classification, was devised in 1938 by M. Waldmeier. In this activity, you will use a modified version of the Zürich Method to classify sunspots.
Vocabulary:
Umbra |
The darkest, coolest portion of a sunspot |
Penumbra |
The lighter, warmer area surrounding the umbra of some sunspots |
Pore |
A dark spot on the Sun, essentially a sunspot umbra with no penumbra |
*Unipolar group |
A single spot or a single compact cluster of spots with the greatest distance between two spots of the cluster not exceeding three heliographic degrees. |
*Bipolar group |
Two spots or a cluster of many spots extending roughly east-west with the major axis exceeding a length of three heliographic degrees. |
*Source: Solar Geophysical Data, 474 Supplement, Feb1984, pp. 21-23,
US Dept of Commerce, Boulder CO 80303, USA
Procedure:
There are several neat sunspots and sunspot groups in this image. How do scientists classify all of these sunspots? Today, scientists use a combination of visual and magnetic characteristics. Take a look at the following table. It’s a classification scheme you can use to classify sunspots and sunspot groups, based on their visual appearance.
MODIFIED ZÜRICH CLASSIFICATIONS
Class A |
Individual spots or groups of spots that:
|
Class B |
Spot groups that:
|
Class C |
Spot groups that:
|
Class D |
Spot groups that:
|
Class E |
Spot groups that:
|
Class F |
Spot groups that:
|
Class H |
Individual spots or spot groups that:
|
Number |
Single or Group? |
Unipolar or Bipolar? |
Penumbra? |
Length ( ° ) |
Classification |
8759 |
|||||
8763 |
|||||
8765 |
|||||
8766 |
|||||
8768 |