It is an aging red giant star 90% as massive as the Sun that has cooled and expanded to a radius 54 times greater than it.

Delta, Epsilon, Zeta, and Theta Sagittae are each multiple stars whose components can be seen in small telescopes.

[6] It was regarded as the weapon that Hercules used to kill the eagle (Aquila) of Jove that perpetually gnawed Prometheus' liver.

An amateur naturalist, polymath Richard Hinckley Allen proposed that the constellation could represent the arrow shot by Hercules towards the adjacent Stymphalian birds (which feature in Hercules' sixth labour) who had claws, beaks, and wings of iron, and who lived on human flesh in the marshes of Arcadia—denoted in the sky by the constellations Aquila the Eagle, Cygnus 'the Swan', and Lyra 'the Vulture'—and still lying between them, whence the title Herculea.

[5][a] Sagitta is bordered by Vulpecula to the north, Hercules to the west, Aquila to the south, and Delphinus to the east.

The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "Sge"; American astronomer Henry Norris Russell, who devised the code, had to resort to using the genitive form of the name to come up with a letter to include ('e') that was not in the name of the constellation Sagittarius.

[1] The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of twelve segments (illustrated in infobox).

English astronomer John Flamsteed added the letters x, mistaken as Chi (χ), y and z to 13, 14, and 15 Sagittae in his Catalogus Britannicus.

It is most likely on the red-giant branch of its evolutionary lifespan, having exhausted its core hydrogen and now burning it in a surrounding shell.

[17] Also known as Sham, Alpha is a yellow bright giant star of spectral class G1 II with an apparent magnitude of 4.38, which lies at a distance of 382±8 light-years from Earth.

[27] With an apparent magnitude of 5.77,[28] the main star is a 331-million-year-old yellow giant of spectral type G8 III around 3.09 times as massive as the Sun,[29] that has swollen to 18.37+0.65−0.88 its radius.

[33] Located 155.9±0.9 light-years from Earth, it has a 61.1% chance of being a member of the Hyades–Pleiades stream of stars that share a common motion through space.

[27] At magnitude 6.5, the brighter is a yellow-white main sequence star of spectral type F3 V,[35] located 146.1±0.2 light-years from Earth.

[43] It is surrounded by a faint (visual magnitude 23) planetary nebula, Henize 1–5, that formed when FG Sagittae first left the asymptotic giant branch.

[51] U Sagittae is an eclipsing binary that varies between magnitudes 6.6 and 9.2 over 3.4 days, making it a suitable target for enthusiasts with small telescopes.

They orbit each other close enough that the cooler subgiant has filled its Roche lobe and is passing material to the hotter star, and hence it is a semidetached binary system.

[58] It is a massive neutron star that is ablating its brown dwarf-sized companion which causes the pulsar's radio signals to attenuate as they pass through the outflowing material.

[59] HD 231701 is a yellow-white main sequence star hotter and larger than the Sun, with a Jupiter-like planet that was discovered in 2007 by the radial velocity technique.

[64] It has an L4 brown dwarf substellar companion that is around the same size as Jupiter but 69 times as massive with a surface temperature of between 1,510 and 1,850 K, taking around 73.3 years to complete an orbit around the star.

[67] At a distance of about 13,000 light-years from Earth,[68] it was first discovered by the French astronomer Philippe Loys de Chéseaux in the year 1745 or 1746.