Gamma Cygni (γ Cygni, abbreviated Gamma Cyg, γ Cyg), officially named Sadr /ˈsædər/,[11][12] is a star in the northern constellation of Cygnus, forming the intersection of an asterism of five stars called the Northern Cross.

It bore the traditional name Sadr (also rendered Sadir /ˈseɪdər/ or Sador), derived from the Arabic صدر ṣadr "chest", the same word which gave rise to the star Schedar (Alpha Cassiopeiae).

[17] Consequently, the Chinese name for Gamma Cygni itself is 天津一 (Tiān Jīn yī, English: the First Star of Celestial Ford).

[7] The spectrum of this star shows some unusual dynamic features, including variations in radial velocity of up to 2 km/s, occurring on a time scale of 100 days or more.

Indeed, on the Hertzsprung–Russell diagram, Gamma Cygni lies close to the instability strip and its spectrum is markedly like that of a Cepheid variable.