strange formation is a sun spot and fairly common.the number on the surface correlates with how active the sun is .
spots occur when magnetic fields causes surface temperature to reduce , making a section stand out .
have temperature of up to 4,200 °c -lrb- 7,590 °f -rrb- , compared to 5,500 °c -lrb- 9,930 °f -rrb- of the surrounding solar material .
gordon ewen captured the unique photograph using a large telescope at the bottom of his garden in hertfordshire .