Diffuse Nebula · Sagittarius

M17 Omega Nebula

Magnitude
7
Season
Summer
Difficulty
Easy
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M170.0° field0° rotation
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Omega Nebula (M17) Diffuse Nebula

Observer's guide

About Omega Nebula

Omega Nebula (M17) is catalogued as a diffuse nebula in Sagittarius. Its J2000 position is RA 18:20:47.11, Dec -16:10:17.5, corresponding to 275.1958 degrees RA and -16.1717 degrees Dec. The local catalogue places it about 5,000 light-years away. Its referenced angular extent is approximately 1.63 by 1.63 arcminutes.

Observing tips

StarWatchr rates this as an easy target at magnitude 7. It is associated with summer observing, with midnight placement typically strongest around June. From 52 degrees north its theoretical meridian altitude is about 21.8 degrees; local horizons and the live altitude chart determine the practical window.

A small telescope under reasonably dark skies is a good starting point; use the live altitude chart to choose its highest point.

What to expect

The SIMBAD classification for the matched source is OpC. A published radial velocity value is -44.6 km/s. The SIMBAD record currently connects it to 1708 bibliographic references.

At roughly 1.6 arcminutes across, it benefits from a narrower field and adequate image scale. Use the listed 1.63 by 1.63 arcminute extent to check framing, and treat catalogue magnitude as integrated brightness rather than a direct measure of visual contrast.

Sourced catalogue data

Scientific record

Measurements for M17 are kept separate from practical observing guidance.

Coordinates (J2000/ICRS)
RA 275.195833° · Dec -16.171667°
SIMBAD classification
OpC
Angular extent
1.63′ × 1.63′
Position angle
90°
Surface brightness
16.69 mag/arcsec²
Radial velocity
-44.58 km/s
Redshift
-0.00014868
Linked bibliography
1,708 references
Best midnight placement
June
Observable latitude range
-90° to 73.8°

Source: SIMBAD astronomical database (CDS, Strasbourg) (ODbL; checked 2026-08-09). Catalogue values may change when new measurements are published.

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