Messier Index/M16

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Eagle Nebula
A view of the "Spire" within M16, the Eagle Nebula.
A view of the "w:Spire" within M16, the Eagle Nebula. Courtesy of w:NASA/w:ESA
Observation data: J2000.0 epoch
Type Emission
Right ascension 18h 18m 48s[1]
Declination -13° 49′[1]
Distance 7,000 ly
Apparent magnitude (V) +6.0[1]
Apparent dimensions (V) 7.0arcmins
Constellation Serpens
Physical characteristics
Radius 70×55 ly (cluster 15 ly)
Absolute magnitude (V) -8.21
Notable features 5.5 million years old
Other designations Messier 16, NGC 6611,[1], Sharpless 49, RCW 165, Gum 83

The Eagle Nebula (catalogued as Messier 16 or M16, and as NGC 6611) is a young w:open cluster of w:stars in the w:constellation w:Serpens, discovered by w:Jean-Philippe de Cheseaux in 1745-46. Its name derives from its shape which is reminiscent of an w:eagle. It is the subject of a famous photograph by the w:Hubble Space Telescope, which shows pillars of star-forming gas and dust within the nebula.

Characteristics

The Eagle Nebula is part of a diffuse w:emission nebula, or H II region, which is catalogued as w:IC 4703. This region of active current star formation is about 6,500 w:light-years distant. The tower of gas that can be seen coming off the nebula is approximately 57 trillion miles (97 trillion km) high.

The brightest star in the nebula has an w:apparent magnitude of +8.24, easily visible with good binoculars.

'Pillars of Creation' region

The "Pillars of Creation" within the Eagle Nebula. Courtesy of w:NASA/w:ESA

Images made in 1995 by Jeff Hester and Paul Scowen using the w:Hubble Space Telescope greatly improved scientific understanding of processes inside the nebula. One of these, a famous photograph known as the "w:Pillars of Creation", depicts a large region of star formation. Its small dark areas are believed to be w:protostars. The pillar structure of the region resembles that of a much larger star formation region, imaged with the w:Spitzer Space Telescope in 2005, in Cassiopeia, which is designated W5 and has been dubbed the "Mountains of Creation".[2]

Combinations of w:X-ray images from the Chandra observatory with Hubble's "Pillars" image have shown that X-ray sources (from young stars) do not coincide with the pillars, but instead randomly dot the area.[1] This suggests that star formation may have peaked approximately one million years ago in the Eagle Nebula and any protostars in the pillar's EGGs are not yet hot enough to emit X-rays.[citation needed]

In early 2007, scientists using the Spitzer discovered evidence that potentially indicates the Pillars were destroyed by a nearby w:supernova explosion about 6,000 years ago, but the light showing the new shape of the nebula will not reach w:Earth for another millennium.[3]

In fiction

See Eagle Nebula in fiction.

External links

References