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portrait of Galileo Are Those Sunspots Really on the Sun?

Data Analysis:

  1. First, you're going to transfer your sunspot data onto the table for your Sunspot Speed Graph. Note that you will need to figure out the distance, in centimeters, traveled by the sunspot groups each day. You will then make a graph with the group's longitude on the horizontal axis, and its apparent speed in centimeters per day on the vertical axis.
    (As an optional assignment, you can also record the group's speed in degrees of longitude per day, and plot it on a separate graph.)

  2. Pick your best sunspot group, the one for which you have the most data. What you want to find is how far that group appeared to travel across the Sun's disk. Remember to measure to the center of the spot or spot group!

  3. To figure out how far the sunspot group moved from the first to second day, subtract your measured distance (the one you measured on your sketch from the edge of the Sun) of the first day from the measured distance of the second day. (e.g. if your Day #1 = 3 cm and Day #2 = 4.5 cm., the distance would be 4.5-3 = 1.5 cm) Now, graph that point above the longitude measurement for the second day.

  4. Figure out how far the group moved between each of the rest of your days, and place the points on the graph. (If you have a day missing, figure the distance the spot group moved in 2 days and use half that amount for each of the 2 days.)

  5. Once your data is plotted, draw a line/curve between the points. To minimize recording errors, graph one or two more sunspot groups just as you did the first.

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