The Eagle Nebula is a splendid diffuse nebula surrounding a cluster that includes many young O-type and B-type stars. Star formation is in progress in this nebula. The gas and dust in the nebula collapse under the force of gravity until the mass grows to the point that the heat and pressure generated at the core of the contracting mass is sufficient to ignite nuclear fusion. The highly luminous hot blue giant stars formed in this region generate solar winds that blow residual gas and dust away from the new stars. The resulting shock wave compresses interstellar gas initiating new regions of gravitational collapse that may form further stars. In some nearby areas where other proto-stars are still in the process of forming, the gas and dust surrounding the proto-star may be sufficiently bound by gravity to the proto-star mass to resist the stellar winds, resulting in the formation of globules, or small dark nebulae. The pockets of gas that remain, after the surrounding cloud is blown away by the stellar winds, can form towering sharply-defined pillars such as those visible in the center of this nebula. The three giant pillars of creation in the center of this nebula were made famous by a detailed Hubble Space Telescope image of those formations. The giant hot stars that are forming in the cluster embedded in the Eagle Nebula are short lived, and will explode as supernovae in a relatively short time. The expanding shock wave from a supernova explosion will also compress interstellar gas and trigger more star formation. Think of all of the turmoil and disturbance that is taking place right before your eyes as you admire this spectacular nebula in Serpens.
The Eagle Nebula is about 8000 light-years away in the Sagittarius spiral arm of our Milky Way Galaxy. The total mass of this nebula exceeds 12,000 solar masses. The nebula appears predominantly blue-green in this false color image, because the data taken with narrow band filters was arbitrarily combined to make a color image. The color here is the same as that used in many Hubble Space Telescope images taken with similar filters. In normal photographs, the Eagle Nebula appears red.
The first person to observe the scattered star cluster immersed in the Eagle Nebula was P.L.de Cheseaux, in 1746. However, in June 1764, Charles Messier was the first to notice a "faint light" around the star cluster that appeared to be a nebula. Messier included this object in his first publication of the Messier List. E.E. Bernard is credited as being the first to record the nebulosity photographically.
This is a tri-color CCD composite image taken with an SBIG STL-11000M CCD using Ha, O-III, and S-II narrow band filters. The telescope was a Takahashi FCT-150 refractor at f7 on a Takahashi NJP Temma mount. The data for this image was acquired over the course of seven nights from my backyard in Scottsdale, Arizona.
M16 (NGC 6611)
Constellation: Serpens Cauda
RA: 18h 18m 48s Dec: -13d 47' 50" (J2000)
April 5, 14, 28 & 30 and May 3, 4 & 5, 2008
Image by Sid Leach
Complete list of images.
Description of equipment used to acquire images.
Feedback and comments should go to Sid