Some stars only use iron (5)
I believe the answer is:
orion
'some stars' is the definition.
(Orion is a constellation)
'only use iron' is the wordplay.
'only' becomes 'o' (this could be a standard abbreviation of which I'm unaware).
'use' indicates anagramming the letters.
'iron' is an anagram of 'rion'.
'o'+'rion'='ORION'
Can you help me to learn more?
(Other definitions for orion that I've seen before include "Great hunter of Greek myth, and a constellation" , "Heavenly figure" , "Greek hunter became a constellation" , "Hunter slain by Artemis" , "He hunted" .)