Sirius follows Jack (3,4)

I believe the answer is:

dog star

'sirius' is the definition.
(Sirius is the Dog Star)

'follows jack' is the wordplay.
'follows' becomes 'dogs' (dog can mean to follow).
'jack' becomes 'tar' (both are informal terms for sailor).
'dogs'+'tar'='DOG-STAR'

(Other definitions for dog star that I've seen before include "heavenly body?" , "Part of 8 [CANIS MAJOR]" , "Sirius in the sky" , "Night light" , "Sirius may also be arts god" .)

I've seen this clue in The Globe and Mail.

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