Cat’s energy captured by an artist (6)
I believe the answer is:
angora
'cat's' is the definition.
(Angora is an example)
'energy captured by an artist' is the wordplay.
'energy' becomes 'go' (I've seen this in other clues).
'captured by' is an insertion indicator.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'an'+'ra'='anra'
'go' placed into 'anra' is 'ANGORA'.
(Other definitions for angora that I've seen before include "Soft yarn from goat" , "Yarn made from hair of goats or rabbits" , "Yarn or fabric from hair of goats or rabbits" , "Wool from hair of goats" , "Fur of rabbit - hair of goat" .)