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Lagoon Nebula and the Trifid Nebula (M8 & M20) HaRGB Sagittarius
EQ8 TS 130mm APO, Baader RGB & Ha, ASI ZWO 6200mm-pro - about 20 mins data. DSS, Cs6, Pixinsight
The Lagoon Nebula (catalogued as Messier 8 or M8, NGC 6523, Sharpless 25, RCW 146, and Gum 72) is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as an H II region.
The Lagoon Nebula was discovered by Giovanni Hodierna before 1654[4] and is one of only two star-forming nebulae faintly visible to the eye from mid-northern latitudes. Seen with binoculars, it appears as a distinct oval cloudlike patch with a definite core. Within the nebula is the open cluster NGC 6530.[5]
The Lagoon Nebula is estimated to be between 4,000-6,000 light-years away from the Earth. In the sky of Earth, it spans 90' by 40', which translates to an actual dimension of 110 by 50 light years. Like many nebulas, it appears pink in time-exposure color photos but is gray to the eye peering through binoculars or a telescope, human vision having poor color sensitivity at low light levels. The nebula contains a number of Bok globules (dark, collapsing clouds of protostellar material), the most prominent of which have been catalogued by E. E. Barnard as B88, B89 and B296. It also includes a funnel-like or tornado-like structure caused by a hot O-type star that emanates ultraviolet light, heating and ionizing gases on the surface of the nebula. The Lagoon Nebula also contains at its centre a structure known as the Hourglass Nebula (so named by John Herschel), which should not be confused with the better known Engraved Hourglass Nebula in the constellation of Musca. In 2006 the first four Herbig–Haro objects were detected within the Hourglass, also including HH 870. This provides the first direct evidence of active star formation by accretion within it.[2]
The Trifid Nebula (catalogued as Messier 20 or M20 and as NGC 6514) is an H II region in the north-west of Sagittarius in a star-forming region in a nearby spiral arm's Scutum-centered part.[3] It was discovered by Charles Messier on June 5, 1764.[4] Its name means 'three-lobe'. The object is an unusual combination of an open cluster of stars, an emission nebula (a relatively dense, red-yellow portion), a reflection nebula (the mainly NNE blue portion), and a dark nebula (the apparent 'gaps' in the former that cause the trifurcated appearance also designated Barnard 85). Viewed through a small telescope, the Trifid Nebula is a bright and peculiar object, and is thus a perennial favorite of amateur astronomers.[5]
The most massive star that has formed in this region is HD 164492A, an O7.5III star with a mass more than 20 times the mass of the Sun.[6] This star is surrounded by a cluster of approximately 3100 young stars.[7] -Wikipedia
Lagoon Nebula and the Trifid Nebula (M8 & M20) HaRGB Sagittarius
EQ8 TS 130mm APO, Baader RGB & Ha, ASI ZWO 6200mm-pro - about 20 mins data. DSS, Cs6, Pixinsight
The Lagoon Nebula (catalogued as Messier 8 or M8, NGC 6523, Sharpless 25, RCW 146, and Gum 72) is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as an H II region.
The Lagoon Nebula was discovered by Giovanni Hodierna before 1654[4] and is one of only two star-forming nebulae faintly visible to the eye from mid-northern latitudes. Seen with binoculars, it appears as a distinct oval cloudlike patch with a definite core. Within the nebula is the open cluster NGC 6530.[5]
The Lagoon Nebula is estimated to be between 4,000-6,000 light-years away from the Earth. In the sky of Earth, it spans 90' by 40', which translates to an actual dimension of 110 by 50 light years. Like many nebulas, it appears pink in time-exposure color photos but is gray to the eye peering through binoculars or a telescope, human vision having poor color sensitivity at low light levels. The nebula contains a number of Bok globules (dark, collapsing clouds of protostellar material), the most prominent of which have been catalogued by E. E. Barnard as B88, B89 and B296. It also includes a funnel-like or tornado-like structure caused by a hot O-type star that emanates ultraviolet light, heating and ionizing gases on the surface of the nebula. The Lagoon Nebula also contains at its centre a structure known as the Hourglass Nebula (so named by John Herschel), which should not be confused with the better known Engraved Hourglass Nebula in the constellation of Musca. In 2006 the first four Herbig–Haro objects were detected within the Hourglass, also including HH 870. This provides the first direct evidence of active star formation by accretion within it.[2]
The Trifid Nebula (catalogued as Messier 20 or M20 and as NGC 6514) is an H II region in the north-west of Sagittarius in a star-forming region in a nearby spiral arm's Scutum-centered part.[3] It was discovered by Charles Messier on June 5, 1764.[4] Its name means 'three-lobe'. The object is an unusual combination of an open cluster of stars, an emission nebula (a relatively dense, red-yellow portion), a reflection nebula (the mainly NNE blue portion), and a dark nebula (the apparent 'gaps' in the former that cause the trifurcated appearance also designated Barnard 85). Viewed through a small telescope, the Trifid Nebula is a bright and peculiar object, and is thus a perennial favorite of amateur astronomers.[5]
The most massive star that has formed in this region is HD 164492A, an O7.5III star with a mass more than 20 times the mass of the Sun.[6] This star is surrounded by a cluster of approximately 3100 young stars.[7] -Wikipedia