Small model encapsulating Queen of the Stars? (8)
I believe the answer is:
sidereal
'of the stars?' is the definition.
(sidereal means relating to the stars)
'small model encapsulating queen' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'model' becomes 'ideal' (ideal is a kind of model).
'encapsulating' is an insertion indicator (I've seen this in other clues).
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'ideal' enclosing 'er' is 'idereal'.
's'+'idereal'='SIDEREAL'
(Other definitions for sidereal that I've seen before include "Full of stars" , "Realised (anag) -- relating to the stars" , "Like stars" , "involving stars" , "Relating to the constellations" .)