Upsilon Sagittarii [SEP] constellation
Upsilon Sagittarii
Upsilon Sagittarii (Upsilon Sgr, υ Sagittarii, υ Sgr) is a spectroscopic binary star system in the constellation Sagittarius. Upsilon Sagittarii is the prototypical hydrogen-deficient binary (HdB), and one of only four such systems known. The unusual spectrum of hydrogen-deficient binaries has made stellar classification of Upsilon Sagittarii difficult.
System.
υ Sgr is a binary system with an orbital period of 137.939 days and is approximately 1,672 light years from Earth. The primary star dominates the visible
meaning 'the brightest of the town'.
This system, together with Zeta Sagittarii and Sigma Sagittarii may have been the Akkadian "Gu-shi-rab‑ba", 'the Yoke of the Sea'.
In Chinese, (), meaning "Establishment", refers to an asterism consisting of Pi Sagittarii, Xi² Sagittarii, Omicron Sagittarii, 43 Sagittarii, Ro¹ Sagittarii and Upsilon Sagittarii. Consequently,the Chinese name for Pi Sagittarii itself is (, .)
Properties.
The spectrum of the system