River drum - Kako

...It is also known as Inukai-boshi, and is thought to have been a Japanese name before the introduction of the Tanabata legend. According to documents such as the Records of the Grand Historian (Tianguan Shu) and the Erya (Shakuten), it is clear that in China up until the Late Han Dynasty, the three stars α, β, and γ in Aquila were seen as being shaped like a large drum and were called Kako (meaning a large drum on the banks of the Milky Way). With the establishment and spread of the Tanabata legend, it is thought that Altair, which represents the constellation of Cow, one of the 28 constellations, handed over its name to Kako, which is located to the north. ...

*Some of the terminology explanations that mention "Kawako" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…また，犬飼星の別称もあり，七夕説話伝来以前の和名かと思われる。《史記》天官書，《爾雅（じが）》釈天などの文献によると，中国では後漢のころまでわし座のα,β,γ3星を大鼓の形に見て河鼓（かこ）(天の川のほとりの大鼓の意)と呼んでいたことが明白である。七夕説話の成立と流布に伴い，二十八宿中の〈牛宿〉を示す〈牽牛星〉が，その北に位置する〈河鼓〉に名称を譲り渡したと考えられる。…

※「河鼓」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