Accurate optical astrometry would locate these peaks relative to the nucleus as defined by the radio core, and so resolve this ambiguity.
The subject of Astrophysics does not admit of so definite a subdivision as that of Astrometry.
A " best fit " between the detections and the optical background is used to precisely fix the astrometry of each field.
Careful calibration of the relative positioning and nonlinear optical distortion is required in order to do astrometry using WFC data.
The descriptive branch found its principle of development in the growing powers of the telescope, and had little to do with mathematical theory; which, on the contrary, was closely allied, by relations of mutual helpfulness, with practical astronomy, or " astrometry."