Sagitta is a constellation in the northern hemisphere. It is the third smallest constellation in the sky. Its name is Latin for "arrow." It was one of the constellations listed by the Greek astronomer Ptolemy in the 2nd century. Because its shape resembles that of an arrow, a number of cultures identified it with the weapon: Greeks, Romans, Hebrews and Persians among others.
In Greek mythology, Sagitta is associated with the arrow that Heracles used to kill the eagle, represented by the constellation Aquila
, that Zeus had sent to gnaw on Prometheus' liver as punishment for stealing fire from Olympus. In another myth, Sagitta represents the arrow that Heracles shot at the Stymphalian birds, flying creatures with claws, wings and beaks of iron, that ate human flesh. The Greek astronomer Eratosthenes said that Sagitta represented the arrow Apollo used to exterminate the Cyclopes because they had forged the thunderbolts that Zeus used to kill Apollo's son, the healer Asclepius. (Asclepius is represented by the constellation Ophiuchus
.) Another myth identifies the arrow with the one that belongs to Eros, the god of love.
The constellation Sagitta occupies an area of 80 square degrees and contains one star with known planets. It can be seen at latitudes between +90° and -70° and is best visible at 9 p.m. during the month of August. Sagitta lies near the equator and can be seen from any location on Earth with the exception of the Antarctic circle.
Sagitta does not have any stars brighter than fourth magnitude. The brightest star in the constellation is 
gamma Sagittae, which marks the tip of the arrow. It is a rare class M star, a red giant, visible to the naked eye. Gamma Sagittae is 275 light-years distant and has luminosity 640 times that of the Sun.
delta Sagittae, the second brightest star, is a magnitude 4 binary star, approximately 450 light-years distant. Its components are a class M bright giant and a class A dwarf.
alpha Sagittae, the third brightest star, is a yellow bright giant, approximately 475 light-years distant. It is four times more massive and 340 times brighter than the Sun. The star is also known by its traditional names, Sham or Alsahm ("arrow").
beta Sagittae is a G class yellow giant star similar to our Sun. It is about 467 light-years distant.
Another notable star is 
15 Sagittae, a magnitude 6 binary star that consists of a yellow main sequence dwarf and a brown dwarf companion.
Sagitta has a couple of interesting deep sky objects. Messier 71 (NGC 6838) is a bright, large globular star cluster that can be spotted between 
delta and 
gamma Sagittae. It is 18,000 light-years distant. NGC 6839, a compact star cluster in Sagitta, contains about eleven magnitude 11 stars.
Sagitta belongs to the Hercules family of constellations, along with Hercules
, Corona Australis
, Triangulum Australe
Constellations directly bordering Sagitta are Vulpecula