Deneb, brightest star in the constellation Cygnus; Bayer designation Alpha Cygni; 1992 position R.A. 20^h41.2^m, Dec. +45°15'. It is a white supergiant of spectral class A2 Ia; its intrinsic brightness (about 60,000 times as luminous as the sun) is the greatest of all the bright stars. Thus, even though it is also one of the most distant bright stars, being about 1,600 light-years from the earth, it has an apparent magnitude of 1.25, making it one of the 20 brightest. Its name is from the Arabic meaning "hen's tail," referring to its position in the constellation.