Solar Photosphere
The photosphere is the Sun's extremely thin visible surface layer named after the Greek word for light. It's about 550 km thick and the temperature varies from about 6600 K up to the minimum at about 4300 K degrees.
Figure 1 shows the large active region 9393 and many sunspots on March 26, 2001. The photospere was observed with MDI on borad SOHO. Figure 2 shows the corresponding magnetogram observed with MDI. Figure 3 shows a sunspot observed on La Palma with the Swedish solar telescope on June 5, 1993. The spot is surrounded by the granulation (dark and bright patterns).
Formation of sunspots and active regions Solar activity