Solar blemish (7)
I believe the answer is:
sunspot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">solar blemish</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sunspot that I've seen before include "cause of magnetic storm" , "Dark cool patch on the surface of our nearest star" , "Cool solar area" , "Cool darker patch on our star" , "warm place" .)