Eta Sagittarii

Starbox short
name=η Sagittarii
epoch=J2000.0
constell=Sagittarius
ra=18^h 17^m 37.6^s
dec=-36° 45' 42"
spectral=M2III
appmag_v=+3.10
absmag_v=-0.20
dist_ly=149 ± 6
dist_pc=46 ± 2
names=HR 6832, HD 167618, SAO 209957, HIP 89642, CCDM 18176-3646

Eta Sagittarii (η Sgr / η Sagitarii) is a star system in the constellation Sagittarius. The star system is 149 light years from Earth. It has the rarely used traditional names Sephdar (Arabic الصفدر "al-safdar"), meaning "Violent Warrior", and the Latin Ira Furoris, meaning "Fierce Wrath" or "Raging Anger" (of the Archer).

It was formerly known as "Beta Telescopii" (β Tel).

The primary component, η Sagittarii A, is a spectral type M3.5 red giant. It is a variable star with small magnitude fluctuations between +3.08 and 3.12, and is classified as an irregular variable.

The brightest companion, η Sagittarii B, is spectral class F dwarf star, with an apparent magnitude of +7.77. It is at a distance of 165 Astronomical Units from the primary and takes approximately 1 300 years to make one orbit. The two stars are separated by 3.6 arcseconds on the sky.

Farther out are two dimmer members of the system, the 13th magnitude η Sagittarii C, separated from A by 33 arcseconds, and the 10th magnitude η Sagittarii D, 93 arcseconds from A.

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