The Bayer designation Tau Aquarii (τ Aqr / τ Aquarii) is shared by two star systems, in the constellation Aquarius:
They are separated by 0.65° on the sky.
All of them were member of asterism 羽林軍 (Yǔ Lín Jūn), Palace Guard, Encampment mansion.
References
Tau Aquarii Wikipedia(Text) CC BY-SA