Omega Nebula
What is Omega Nebula?
Nebulae· Distance 5,500 ly. A bright nebula with many nicknames — Swan, Omega, Horseshoe, Checkmark. One of the brightest and most massive star nurseries in our galaxy, its swimming-swan shape shows even in binoculars. It lies just south of the Eagle Nebula.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Omega Nebula is in your sky right now: https://nowsky.org/solar/sky?sel=omega nebula — location and time set automatically, no login.
Its place in the sky
A nebula, in the direction of Scutum, spanning about 11 arcminutes of sky — 0.4 times the width of the full Moon.
Distance and scale
| Distance | ~5,500 ly |
|---|---|
| Size | ~15 ly (bright core) |
| Type | emission nebula |
| Constellation | Sagittarius |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Discovery and name
Found by de Chéseaux in 1745; also the Swan, Horseshoe or Lobster from its shape.
Frequently asked
- How far is Omega Nebula from Earth?
- ~5,500 ly.
- What kind of object is Omega Nebula?
- emission nebula.
- Where in the sky is Omega Nebula?
- In the direction of Scutum.
- Where is Omega Nebula in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
What shows is a tenth — the giant molecular cloud behind
The bright part of the Omega Nebula is 15 light-years across, but behind and beside it stretches a giant molecular cloud of more than 30,000 solar masses. The swan shape seen in visible light is only a thin layer at the cloud's edge, warmed to glowing by young stars; in radio and infrared the nebula spreads ten times wider than in photographs, and star formation is under way in the dark interior.
Within the cloud stars form in sequence — the light and winds of the first generation compress neighbouring gas into the next — so the south-west of the Omega already holds a cluster while infrared reveals protostars just being born in the dark north-east. The cluster NGC 6618 that lights the nebula, about a million years old, is the most recent generation in that chain.
The nebula in depth
The Omega Nebula (M17) is an emission nebula about 5,500 light-years away near the border of Sagittarius and Serpens. Its bright core spans about 15 light-years, but with the surrounding fainter gas it exceeds 40. De Chéseaux discovered it in 1745, and the present name comes from its likeness to the Greek letter omega, though every observer sees something different — a swan, a horseshoe, a checkmark.
It is one of the brightest and most massive star-forming regions in the galaxy, holding about 800 solar masses of gas. The cluster that lights it is only a million years old, and its hot stars hide behind dust so they are hard to see in visible light. Hubble and James Webb images reveal waves of gas sculpted by stellar winds and protostars buried in the dust.
In the Sky view, look into the Milky Way above the Sagittarius teapot on summer evenings, just below the Eagle Nebula (M16). At 6th magnitude it is bright enough that binoculars show the swimming swan, and a small telescope brings out the contrast between neck and body. After the Orion Nebula, it is the next nebula to recommend to a beginner.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.