Sagitta
What is Sagitta?
Constellations· Summer evenings (N) · tiny arrow inside the Summer Triangle. A little arrow lying in the middle of the Summer Triangle. The third-smallest constellation, yet its four stars really do line up like a dart. Said to be the arrow Heracles shot at the eagle, or one of Eros's. Zoom in north of Altair in the Sky view.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Sagitta is in your sky right now: https://nowsky.org/solar/sky?sel=con:Sagitta — location and time set automatically, no login.
Stars of the figure
| Star | Magnitude |
|---|---|
| Gamma Sagittae | 3.5 |
| Delta Sagittae | 3.8 |
| Sham | 4.4 |
The 3 brightest of the 3 stars used in the figure (2 lines). Lower magnitude means brighter.
Deep-sky objects near this constellation
Constellation basics
| Season | summer evenings (N) |
|---|---|
| Brightest star | Gamma Sagittae (3.5) |
| How to find | between Altair and Albireo |
| Area rank | 88 (세 번째로 작음 / 3rd smallest) |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- When can I see Sagitta?
- summer evenings (N).
- How do I find Sagitta?
- between Altair and Albireo.
- What is the brightest star in Sagitta?
- Gamma Sagittae, magnitude 3.5.
- Where is Sagitta in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
WZ Sagittae — a star that erupts every 23 years
Sagitta holds a star that sits at 15th magnitude, within reach only of large telescopes, and roughly every 23 years brightens to 8th: WZ Sagittae, with eruptions recorded in 1913, 1946, 1978 and 2001. It is a dwarf nova, in which material drawn from a companion piles up in a disk around a white dwarf and collapses inward all at once; the companion is a brown-dwarf-class object of a few Jupiter masses, so the disk fills very slowly and the interval is long.
The two orbit each other every 82 minutes, among the shortest orbital periods known. The 2001 outburst was anticipated and became the first dwarf nova watched by telescopes worldwide from its first day, leaving the standard record of a disk collapsing. The next is expected from the mid-2020s onward, but the exact time cannot be predicted. Inside the little arrow sits a clock waiting to go off.
The constellation in depth
Sagitta is one of Ptolemy's 48 constellations — tiny, but very old. Greek writers variously called it the arrow Heracles used to kill the eagle tormenting Prometheus, one Apollo shot at the Cyclopes, or an arrow of Eros, the god of love. With Aquila the eagle right next door, the first story fits the sky best.
Alpha and Beta mark the fletching, Delta the shaft and Gamma the point. Halfway along sits M71, a loose cluster that blurs the line between globular and open clusters, faintly visible in binoculars. Covering only 0.2% of the sky, it ranks 86th of 88 in area.
On July–September evenings, find the overhead Summer Triangle (Vega, Deneb, Altair), then move about 10 degrees from Altair toward Albireo to spot the little arrow. Its stars are 3.5–4.4 magnitude, so binoculars help in town. In the Sky view, zoom in north of Altair.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.