Star recalls the extremes of a vivid imagination (4)
I believe the answer is:
nova
'star' is the definition.
(I know that nova is a type of star)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for nova that I've seen before include "Star that suddenly increases in brightness" , "Star showing a sudden temporary increase in brightness" , "Kind of star" , "Faint star that suddenly flares into brightness and then fades again" , "Star briefly brightening" .)