What aspect of stellar motion does the astrometry technique monitor, distinguishing it from radial velocity?

Answer

The star’s positional shift across the sky.

Astrometry observes the star's absolute position over time, tracking the tiny path or wobble the star traces across the sky due to the planet's tug.

What aspect of stellar motion does the astrometry technique monitor, distinguishing it from radial velocity?
measurementastronomyexoplanetsdetection