Sources for Sun:

Dailt, Robert, The Sun, Franklin Watt, NY 1994

"The Sun," World Book Multimedia Encyclopedia. Chicago: World Book 
Inc., 1997.

"The Sun Fact Sheet," National Space Science Data Center. Online. 
16 January 1999.  
http://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html 

Photo Credits for the Sun:

Sun (orange): Current solar image from the NASA Goddard Space Flight Center. 
Courtesy of SDAC and NASA. (SOHO Extreme Ultraviolet  Imaging Telescope (EIT) 
full-field He II/Si XI 304 Å taken 19:19:11 1999/07/14) 
http://umbra.nascom.nasa.gov/images/latest_eit_304.gif  or 
http://umbra.gsfc.nasa.gov/eit/eit_full_res.html

Sun (blue): (latest_eit_171.gif) taken by SOHO extreme ultraviolet imaging 
telescope (EIT) full-field Fe IX, X 171 A . Images from NASA Goddard Space 
Flight Center. taken 2000/08/04 at 13:0014.Courtesy of NASA. 
http://umbra.gsfc.nasa.gov/images/latest.html. 

Sun (dark red and black): (yohkoh_950912.jpg) taken by joint ISAS/NASA 
spacecraft Yohkoh. Images are soft X-rays of the sun. taken 12 Sept. 1995. 
Courtesy of NASA/NSSDC.

Sun (green): (latest_eit_195.gif) same as the orange and blue but is 
Full-field Fe XII 195 A images. taken on 2000/08/10 at 00:00:11. same 
site as sun blue. Courtesy of NASA Goddard Space Flight Center. 

Sunspots: (latest_mdi_igram.gif) taken by SOHO Michelson Doppler Imager 
MDI 6767 A, continuous images from Stanford University. taken 2000/08/09 at 
12:12 UT. Courtesy of NASA/Stanford University. 

Small GIF animation of sun: taken also by the SOHO EIT. made into a GIF 
animation by the EIT Consortium. Courtesy of EIT Consortium.