Gamma Sagittarii

The Bayer designation Gamma Sagittarii (γ Sgr / γ Sagittarii) is shared by two star systems in the constellation Sagittarius, γ¹ Sagittarii and γ² Sagittarii. They are separated by 0.86° on the sky, and can be resolved by the human eye.

γ¹ Sagittarii

Gamma-1 Sagittarii (γ¹ Sgr / γ¹ Sagittarii) is a cepheid variable star in the constellation Sagittarius. It is often referred to by its variable star designation, W Sagittarii.

This variable star changes in apparent magnitude from +4.3 to +5.1 with a period of 7.59 days. Its change in brightness is accompanied by a change in spectral classification, from G1 to F4. Based on its variablility, W Sagittarii has been estimated to be approximately 1500 light years from Earth.

W Sagittarii also shows evidence of being a close binary star, as well has having two more distant 13th magnitude companions, W Sagittarii B, and C separated by 33 and 48 arcseconds respectively.

γ² Sagittarii

Gamma-2 Sagittarii (γ² Sgr / γ² Sagittarii) is a star in the constellation Sagittarius. It also has the traditional names Nash, Alnasl, Nasl, or El Nasl, which are derived from the Arabic النصل an-naşl meaning arrowhead.

Alnasl is a spectral type K0 giant, and has an apparent magnitude of +2.98. Alnasl is 96 light years from Earth.