Is a Galaxy Unresolved at 10 Arc Seconds with 15 Arc Second Resolution?

[Airsteve0]

This question may be quite trivial but I was wondering if you were observing a galaxy that was say 10 arc seconds in diameter with a telescope whose diffraction limited resolution was 15 arc seconds would the galaxy appear completely unresolved or just "blurry".

 

[Drakkith]

That depends on what you mean by "unresolved". The light would appear, but it would be very blurry to the point that you wouldn't be able to see any detail, just a fuzzy spot.