Messer 16 (NGC 6611 and IC 4703), Eagle Nebula
Constellation - Serpens Cauda
Distance - 7,000 light years,
Estimated age - 5.5 million years old.
This object is a combination of an emission nebula and open cluster. The open cluster, designated as NGC 6611, was first described by Philippe Loys de Cheseaux in 1745-6. The nebulosity, designated as IC 4703, was first described by Charles Messier in 1764.
The Eagle Nebula is located in the next inner spiral arm of the Milky Way Galaxy and is believed to be about 7,000 light years distant.
This area is known to be an area of active star formation. The long finger-shaped objects in the the image [also called "elephant trunks"] are massive columns of cold gas that extend from a vast cloud of molecular hydrogen. Inside these light-years-long columns the interstellar gas is dense enough to collapse under its own weight and is in the process of forming new stars. The emission nebula shines as a result of the radiation from the bright stars of NGC 6611.
July 5-6, 2008
Luminance - Combination of twenty-four 6 minute red-filtered sub exposures.
Color - A 2005 RGB image consisting of 50 minutes per channel.
Mt. Laguna, Cleveland National Forest, San Diego County, California;
RC Optical Systems 10" Ritchey-ChrÃ©tien at f/9, Mount - Astro-Physics AP 1200 GTO Camera - ST-10XME