Accurate optical astrometry would locate these peaks relative to the nucleus as defined by the radio core, and so resolve this ambiguity.
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."
He employed in his discussion the radial velocities of 280 stars, spectroscopically determined; and the upshot signally exemplified the community of interests between the rising science of astrophysics and the ancient science of astrometry.
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.