Inconsistent celebrity shows heavenly body (8,4)

I believe the answer is:

variable star

'heavenly body' is the definition.
(variable star is a kind of heavenly body)

'inconsistent celebrity' is the wordplay.
'inconsistent' becomes 'variable' (similar in meaning).
'celebrity' becomes 'star' (a star is a celebrity or famous person).
'variable'+'star'='VARIABLE STAR'

'shows' is the link.

(Another definition for variable star that I've seen is " One not shining consistently".)

I've seen this clue in The Daily Express.

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