Bright star turns savage into someone wise... (4)

I believe the answer is:

nova

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'bright star' is the definition.
(I've seen this in another clue)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for nova that I've seen before include "Newly bright star" , "Star that suddenly increases in brightness" , "Star briefly brightening" , "A new flaring star" , "Star that suddenly becomes brighter for a time" .)

I've seen this clue in The Irish Times.

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