Gold particle of a constellation (5)
I believe the answer is:
orion
'a constellation' is the definition.
(Orion is an example)
'gold particle' is the wordplay.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'particle' becomes 'ion' (I've seen this before).
'or'+'ion'='ORION'
'of' acts as a link.
(Other definitions for orion that I've seen before include "His belt is in the heavens" , "He hunted" , "Rigel constellation" , "Belted constellation" , "hero" .)