The Blue knots associated with the radio-emitting jet that originates from the central Black Hole or Massive Dark Object of NGC 5128, objects which are presumably made of luminous and hot OB stars, are very prominent in the Far-ultraviolet, as discussed in the recent NGC 5128 thread in the observational astronomy forum.
However, these knots are faint and very small when imaged at optical wavelengths. A good idea of how small and how faint can be obtained from looking at this image which was taken with the ESO/MPG 2.2m telescope with the WFI array of CCDs.
This is a small section of the original image of the entire galaxy:
Note: The combination of the ESO 2.2m telescope and WFI, usually produces images of less than one arcsec res.
In fact, 0.5 arcsec resolution is not uncommon!