The designations of the two constituents as Theta Serpentis AB and C, and those of AB's components - Theta Serpentis A and B - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).
[11] The system bore the traditional name Alya, or Alga, from the Arabic الية ’alyah "fat tail (of a sheep)".
The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.
[16] Consequently, the Chinese name for Theta Serpentis itself is 天市左垣七 (Tiān Shì Zuǒ Yuán qī, English: the Seventh Star of Left Wall of Heavenly Market Enclosure), representing the state Xu (徐).
These two stars are 22 arcseconds apart on the sky, putting them at least 900 AU apart with an orbital period of at least 14,000 years.