The most common and most likely answer to this crossword clue is the 6 letter word CARINA
I've seen this crossword clue in The Guardian
C
A
R
I
N
A
Buddy explains!
The straight part
We know that "the location of Canopus" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case the location of canopus = carina.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CARINA mean?
CARINA noun- A longitudinal ridge or projection like the keel of a boat.
- Part of a papilionaceous flower consisting of two petals, commonly united, which encloses the organs of fructification.
- The keel of the breastbone of birds.
- Any of several features that have a projecting central ridge