Constellation components (5)
I believe the answer is:
stars
'constellation components' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stars that I've seen before include "''What is the ...? What is the ...? '' (Juno and the Paycock)" , "Heavenly bodies" , "Celebs - constellation" , "plays a leading role" , "Leading actors" .)