[The Red Zone]

The team has verified the information by using the relatively new technique of helioseismology, based in part on observations from NASA instruments. This technique tracks sound waves reverberating inside the Sun to reveal details about the interior, much as a doctor might use ultrasound to see inside a patient.

Question I have is, how many sunspot cycles have been observed with this new fangled stuff. If they haven't seen even one yet, I'd wait and see.

[Esther Ruth]

Oh yikes, idunno, there are a lot of great links that you could spend millions of hours on at that web site linked at top of this article. Look at this one that is from the bottom of article. Lots there.
http://www.hao.ucar.edu/