Abstract:
Astrometry is the science of studying positions and motions of the celestial objects.
Astrometry, by its definition, can be considered to be started with the first naked eye
observations of the night sky. Thus, it is one of the oldest divisions of Astronomy.
The sources concerned in astrometry include stars and star clusters of the Milky
Way. To a greater extent, it aims to study positions and motions of other galaxies
and even the cluster of galaxies.
Astrometric measurement techniques had reached a saturation level of accuracy
and the astrometric studies were on a back foot for decades in the last century until
recently when they became vital again owing to the new developments like invention
of CCDs, launching of HIPPARCOS space mission, Hubble Space Telescope and uses
of CCDs Wide Field Images etc. The astrometric accuracies being achieved these
days are far better and the field is expected to revolutionize further with the take
off of the GAIA space mission.
