Stars exhibit proper motion. They move relative to other stars in the sky, albeit very slowly. Due to its proper motion, in 1992, the star Rho Aquilae crossed the boundary of its original constellation, Aquila, to the neighboring Delphinus.
Constellations appear the same for years, and flat-Earthers wrongly use it as “evidence” stars are stationary. In reality, with precise measurements, we know the stars are moving.
References
- Proper motion – Wikipedia
- Rho Aquilae – Wikipedia