You are probably wondering you found it and when, well I can tell you. The person who discovered it was Ptolemy and he found it in 1922. But also the latitude and longitude is 34 and 74 north of the ecliptic. When you want to see the Sagitta, on in the month of August go outside and look for it at 9:00 p.m.
There are two myths for sagitta, one myth is that Apollo killed the Cyclopes with the arrow. The second one is that Sagitta was one of the Arrows with which Heracles killed the eagle that ate the liver of Prometheus. A fact about the sagitta is that it is the 86th constellation.