The Eagle Nebula Messier 16 (M16) is a conspicuous region of active star formation lying some 7,000 light years distant in the constellation Serpens, close to the borders of Scutum and Sagittarius and in the next spiral arm of the Milky Way Galaxy from us. It is visible on the left side of this image. The Eagle Nebula itself (also named IC 4703) consists of a large gaseous and dusty cloud, which is now caused to shine brightly in the red end of spectrum by emission light, excited by the high-energy radiation of its massive hot, young stars. The cluster of stars at its core is also known by the designation NGC 6611. The central core of the nebula is still actively forming new stars.

A dark area on the right side of the M16 in this image is called the "Star-Queen" Nebula (IC 4703). A thin dark "finger" or "trunk" of this associated dark nebula extends to the left towards the open cluster within the Eagle. Note: Due to the scale of the image it is not easily seen in this image. The cluster members surrounding the "head" of the eagle include ten magnitude 8-10 stars with a bright pair of mag 8.5 stars. A dark triangular wedge from this dark nebula helps to form the Eagle's head and is clearly visible on the right side of M16.

Also visible in the wide field narrowband image is the star cluster NGC 6604. This cluster is the bright loose grouping of stars visible on the right side of this image. It is often overlooked in favor of its more prominent neighbor, M16. But the framing of this image, which places the star cluster in a landscape of surrounding gas and dust clouds, shows what a beautiful object NGC 6604 is in its own right.

NGC 6604 is a young star cluster that is the densest part of a more widely scattered association containing about one hundred brilliant blue-white stars. This image also shows the cluster’s associated nebula — a cloud of glowing hydrogen gas that is called Sh2-54 — as well as, associated dust clouds visible in the same region.

NGC 6604 lies about 5500 light-years away in the constellation of Serpens (The Serpent) and is located about two degrees north of the Eagle Nebula in the night sky.

NGC 6604's cluster of hot young stars are helping a new generation of stars to form, by collecting star-making material into a compact region with their strong stellar winds and radiation. This second generation of stars will quickly replace the older generation, as although the brightest young stars are massive, they consume their fuel copiously and live relatively short lives in astronomical terms.

Aside from aesthetics, NGC 6604 has other reasons to draw the gaze of astronomers, as it has a strange column of hot ionised gas emanating from it. Similar columns of hot gas, which channel outflowing material from young star clusters, have been found elsewhere in the Milky Way and other spiral galaxies, but the example in NGC 6604 is relatively nearby, allowing astronomers to study it in detail.

This particular column (often referred to by astronomers as a “chimney”) is perpendicular to the galactic plane and stretches an incredible 650 light-years in length. Astronomers think that the hot stars within NGC 6604 are responsible for producing the chimney, but more research is needed to fully understand these unusual structures.

Notes:

1. Diffraction spikes associated with the brightest stars in this image have been enhanced slightly using Star Spikes by ProDigital Software making for a dramatic effect.

2. Much of the descriptive information here is sourced from the SEDS Organization, from Wikimedia Commons, and from Steve Gottlieb of the Rolling Roof Observatory in California to which full credit is given for their respective content. After all, I really don't claim to know all these factual details about the deep space objects that I image, but I love to learn about them after capturing the images and to share that information with you here.