Brightest star in Lyra (4)
I believe the answer is:
vega
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">brightest star in lyra</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for vega that I've seen before include "Bright star of constellation Lyra" , "Fifth brightest star" , "heavenly body" , "Gave turn to a star" , "First magnitude star" .)