AC (Astronomy)

...The spectral types are also listed. The Carte du Ciel (abbreviated CdC, also known as the Astrographic Catalogue (abbreviated AC)) was started in 1887 by 18 observatories that agreed to share the use of the same type of refracting telescope. The dry plates were 2.° square, with 1 mm corresponding to an angle of 1', and the positions of stars up to 14th magnitude were precisely measured. After a century, it was finally completed and is now being published. ...

*Some of the terminology explanations that mention "AC (astronomy)" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…またスペクトル型も記載してある。カルト･デュ･シエルCarte du Ciel(略称CdC，別名Astrographic Catalogue(略称AC))は，1887年に18の天文台が同型の屈折望遠鏡による分担撮影を協定して観測を開始し，乾板は2.゜2角，1mmが角度1′に相当し，14等までの星の位置を精密に測った。1世紀を経てようやく完成し出版されつつある。…

※「AC（天文）」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報