gday ving
that's exactly what they look like ive seen sunspots (ive seen these with my refractor b4 i got my dob) heaps bigger and more ive seen them appear and disappear. (also had a look once sofar with the dob).
to lign the sun up i use the shadow on the ground technique
some sunspots can be the size of the earth several times over you can fit 180 earths across the diameter ot the sun just for scale
you are gonna have to finish your filter
http://sohowww.nascom.nasa.gov/data/...me-images.html
scroll down and click on the MDI Continuum one once that one comes up you can click on it again for a larger version its the site i use to keep tabs on it or offcourse you can use the one on IIS