ヨハン・バイエル
Johann Bayer gave Thuban the designation Alpha and placed it as the only member of his "secundae" magnitude class in Draco, although its current apparent magnitude of 3.65 means it is 3.7 times fainter than the brightest star in the constellation, Gamma Draconis (Eltanin), which Bayer placed in his "tertiae" magnitude class although its current apparent magnitude is 2.24.