Proper motion is rather slow. Fortunately astronomy can take measurements across the centuries.
"Proper motion was suspected by early astronomers (according to Macrobius, AD 400) but a proof was not provided until 1718 by Edmund Halley, who noticed that Sirius, Arcturus and Aldebaran were over half a degree away from the positions charted by the ancient Greek astronomer Hipparchus roughly 1850 years earlier."
Sensibly, the star catalog is arranged by apparent position from Earth. There are two kinds of motion that need to be accounted for: the precession of the earth, which affects all coordinates uniformly ( http://www.stargazing.net/kepler/b1950.html ) and "proper motion" of the stars themselves: https://en.wikipedia.org/wiki/Proper_motion
Proper motion is rather slow. Fortunately astronomy can take measurements across the centuries.
"Proper motion was suspected by early astronomers (according to Macrobius, AD 400) but a proof was not provided until 1718 by Edmund Halley, who noticed that Sirius, Arcturus and Aldebaran were over half a degree away from the positions charted by the ancient Greek astronomer Hipparchus roughly 1850 years earlier."