ヘンリー・ドレイパーカタログ
The spectrum of Beta Cygni A was found to be composite when it was observed as part of the Henry Draper Memorial project in the late 19th century, leading to the supposition that it was itself double. This was supported by observations from 1898 to 1918 which showed that it had a varying radial velocity. In 1923, the two components were identified in the Henry Draper Catalogue as HD 183912 and HD 183913.