Sun shows beginning, but no ending (4)

I believe the answer is:

star

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'sun' is the definition.
(I've seen this before)

'shows beginning but no ending' is the wordplay.
'beginning' indicates taking the first letters.
'but no ending' becomes 'tar' (I am not sure about this - if you are sure you should believe this answer much more).
The initial letter of 'shows' is 's'.
's'+'tar'='STAR'

Can you help me to learn more?

(Other definitions for star that I've seen before include "Brilliant performer?" , "E.g.Sirius" , "Outstanding actor" , "chamber" , "virtuoso" .)

I've seen this clue in The Daily Express.

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