I guess you'd just want to store the orbital information of that object, as it probably won't stay at a fixed position.
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."