Hi! I was wondering how you plot the sunspots on a diagram/template with degrees on it. In other words, I want to plot a sunspot and calculate the position of it in degrees. I have no idea how to do it but I think it includes the assumption that the rotation axis of the Sun is perpendicular to us. By knowing that we need to compute the apparent longitude of the spot on the Sun. I think that this can be done by measuring the position of the spot..and finally compare the photos taken of the Sun for maybe one week and then get the angular velocity by difference in the logitude position. How do I calculate the longitude position? :S Thanks!