Omega nebula

(redirected from NGC 6618)

Omega nebula

(Swan nebula; Horseshoe nebula; M17; NGC 6618) An emission nebula with a conspicuous bar that lies at a distance of 2200 parsecs in the constellation of Sagittarius, very close to its northern boundary with Scutum. The nebula's apparent magnitude is 7. It is an H II region and a double radio source. The M17SW molecular cloud is a site of massive star formation; the interface between the nebula and M17SW is an example of an edge-on photodissociation region.

Omega Nebula

[ō′meg·ə ′neb·yə·lə]
(astronomy)
A bright H II region in the constellation Sagittarius that is both a bright far-infrared source and a double radio source. Also known as Swan Nebula.
References in periodicals archive ?
M17 is a bright H II region in the Milky Way with a colossal but hidden star cluster cataloged as NGC 6618.
That increase in density, nearly 2 million years ago, kick-started the formation of approximately 12,000 more stars and continues today, making up the huge NGC 6618 star cluster.
The massive O-class stars in NGC 6618 blast out intense ultraviolet radiation that excites the hydrogen gas in the M17 molecular cloud to emit visible light, creating the emission nebula/H II region we're so fond of naming.
These are some of the visible stars of the NGC 6618 cluster.
Although we can't see much of the NGC 6618 cluster, its main concentration of stars is located in the crook between the swan's neck and body.
The object has also been catalogued as Messier 17 (M17) and NGC 6618.