M17 — Omega Nebula
A vast emission nebula in Sagittarius, shaped like a swan or a horseshoe depending on the framing, one of the most active star-forming regions in the Milky Way.
View photos ↓- Object type
- Emission nebula
- Constellation
- Sagittarius
- Designation
- M17 (NGC 6618)
- Distance
- ≈ 5,500 light-years
- Apparent magnitude
- 6.0
- Apparent size
- 20 x 15 arcmin
- Best season
- Summer (best visibility July-August)
The Omega Nebula (M17), also known as the Swan Nebula or Horseshoe Nebula depending on how you picture it, is one of the most active star-forming regions in our galaxy. Its gas is ionized by radiation from young, massive stars that have barely emerged from their parent molecular cloud.
Sitting low on the horizon from our latitudes, it remains tricky to frame properly, but the characteristic swirling structure of its gas and dust filaments is already visible in this image.
Two short sessions were combined for this image: a first one on 2026-07-11/12 (10 s subs), a second on 2026-07-23 (30 s subs), with the Seestar S30 Pro mounted in equatorial mode on the EQ3 and its light pollution filter. Stacked and processed in Siril.
