Tracking Sunspots
The Sun rotates in 25 to36 days. The exact period varies between the Sun's equator (25) and its poles (36). Sunspots are relatively cool, dark areas on the Sun's surface where strong magnetic fields are breaking through the surface. We can watch the Sun rotate by tracking the apparent motion of sunspots from day to day.
Use one of the sunspotter telescopes in an image-projection mode (ask your instructor about this) to view the Sun and record the positions of all the sunspots you can see. Record their positions by sketching the spots directly on your viewing paper. Make at least 4-5 observations of the same spots (that is, observe on 4-5 different, consecutive days). It will be much easier to interpret your data if the observations are made at the same time of day each time. This is because the Sun's equator will be continuously aligned with the ecliptic, but Durango’s point of view changes. In other words, the Sun’s equator will tilt one direction in the morning and the other direction in the afternoon. When you compile your data to determine the sunspot motion, be sure to account for and remove that effect. Indicate the cardinal points (N, S, E, W) on each of your drawings. (Hint: the "drift" of the solar image through the telescope field-of-view due to the Earth's rotation is always from east to west.) See how many sunspot groups you can track.
Equipment Use
You will be introduced to the Sunspotter telescope during your lab section. It will be available to you during the day in the lab. If the room is locked, you can likely find an instructor to open it for you. You will use the sunspotter, then return it to the lab each time you observe. This should take about 10 minutes. Start soon to avoid having trouble with the weather.
Your Data
This project requires observations. This part of your grade will be based on how carefully you recorded and presented your observations. Did you make neat sketches? Did you list date and time on your sketches? Did you make enough observations? Did you make useful observations by tracking the same sunspot groups through at least 4-5 consecutive observations?
You must re-compile your data onto a separate drawing, in which you place many consecutive days of observations on a single drawing to show the rotation of the Sun. To do this, re-draw the Sun, and sketch in the observations from your first day in a particular color; then do the next day in a different color, and so on. Include a complete legend so the reader can tell which spots correspond to which days. Also draw arrows to indicate the motion of the spots. This drawing is the most important part of the lab, so do it neatly and intelligently!
Your Report
You should follow the format found on the report page. In particular, your Data and Results section needs to include a single sketch showing the Sun’s rotation through several days of sunspots. (Compile your data.) You also need to show (and describe) your calculations where you determine the approximate number of days it takes the Sun to rotate, based on the motion of sunspots that you recorded.