Stellar motion

Up to now, it had been assumed that the stars were fixed in the sky. However, upon careful observation of bright stars Sirius, Procyon, and Arcturus, Halley found that they'd moved relative to the observations of Tycho.
 Edmond Halley England 1718 Stellar motion

Up to now, it had been assumed that the stars were fixed in the sky. However, upon careful observation of bright stars Sirius, Procyon, and Arcturus, Halley found that they'd moved relative to the observations of Tycho.