Messier Index/M20

250px Trifid Nebula by the w:Hubble Space Telescope (w:NASA/w:ESA) Trifid Nebula Emission/Reflection w:J2000 18 02 23SIMBAD Astronomical Database Results for NGC 6514 http://simbad.u-strasbg.fr/Simbad 2006-11-16 -23 01 48 2000 - 9000 ly +6.3 ~20 arcmins Sagittarius - - - M20, NGC 6514, Sharpless 30, RCW 147, Gum 76 The Trifid Nebula (catalogued as Messier 20 or M20 and as NGC 6514) is an w:H II region located in Sagittarius. Its name means 'divided into three lobes'. The object is an unusual combination of an w:open cluster of w:stars, an w:emission nebula (the lower, red portion), a w:reflection nebula (the upper, blue portion) and a w:dark nebula (the apparent 'gaps' within the emission nebula that cause the trifid appearance; these are also designated Barnard 85). Viewed through a small w:telescope, the Trifid Nebula is a bright and colorful object, and is thus a perennial favorite of amateur astronomers. Characteristics The Trifid Nebula was the subject of an investigation by astronomers using the w:Hubble Space Telescope in w:1997, using filters that isolate emission from w:hydrogen w:atoms, w:ionized w:sulfur atoms, and doubly ionized w:oxygen atoms. The images were combined into a false-color composite picture to suggest how the nebula might look to the eye. The close-up images show a dense cloud of dust and gas, which is a w:stellar nursery full of embryonic stars. This cloud is about 8 w:light years away from the nebula's central star. A w:stellar jet protrudes from the head of the cloud and is about 0.75 w:light-years long. The jet's source is a young stellar object deep within the cloud. Jets are the exhaust gasses of star formation. Radiation from the nebula's central star makes the jet glow. The images also showed a finger-like stalk to the right of the jet. It points from the head of the dense cloud directly toward the star that powers the Trifid nebula. This stalk is a prominent example of an w:evaporating gaseous globules, or 'EGGs'. The stalk has survived because its tip is a knot of gas that is dense enough to resist being eaten away by the powerful radiation from the star. In January, 2005, w:NASA's w:Spitzer Space Telescope discovered 30 embryonic stars and 120 newborn stars not seen in w:visible light images. Gallery External links Spitzer IR Trifid discoveries Messier 20, SEDS Messier pages Trifid Nebula at ESA/Hubble References