M16 - The Eagle & Star Queen Nebula

Emission Nebula in Serpens

Uploaded 8/23/09

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Below: Comparison of LRGB and G2v calibrated RGB data

This object is another example of greatly improving the compositional aspect of a named nebula to get the best representation of the objects namesake. A small 25 degree rotation veiled a much more dramatic Eagle with spread wings, and the central "Star Queen" (Named by Burnham) in an upright orientation. So many amateur shots of this object requires you to tilt your head to view properly!

Great care was taken on this image to maintain as closely as possible the pinks, and magentas to reds in the original RGB image. A comparison of the two side by side frames shows the similarity, with the addition of L data in the left image yielding a brighter but exactly equal shade of pink to the image on the right. You simply cannot add brightness to an image and not keep exactly the same shade, but the HUE is exactly the same as confirmed by the color analysis tool in Picture Window Pro.

About this Object:

M16 is the brightest nebula in a field of very dim nebulosity in the constellation of Serpens just above the Galactic core. The nebula is illuminated to shine by the bright star cluster NGC6611, which with its hot O and B stars is at 6th magnitude. Such hot illumination yields a much pinker color than the nearby M17, which also lies behind a wall of thin dust, making for a more orange overall hue with very little pink from H beta emission. The nebulosity, which is IC4703 is a huge half a degree across and very extended beyond this field of view, which is 3/4 a degree wide.

Inside the nebula is a dark nebula in the shape of a person holding a book sitting on a throne. This fanciful interpretation, originally brought to light by Robert Burnham in his famous Celestial Handbooks has now become even more famous by the recent Hubble space telescope image of the queens head region. Few imaging techniques bring this nebula to its best as well as incorporating some narrow band hydrogen data. Here, we used a very high transmission 3 nm filter I had specially selected by Custom Scientific for maximum transmission in Halpha.

Instrument: 12.5" f/5 Home made Newtonian Mount: Astrophysics 1200 QMD CCD Camera: SBIG 10XME NABG with Enhanced Water Cooling Guider: SBIG ST4 w/Lumicon Newt Easy Guider Exposure: LRGB = 180:40:40:40 L= 3nm CS Ha AstroDon RGB Combine Ratio: 1: 1.05: 1.11 = G2V Location: Payson, Arizona, Elevation: 5150 ft. Sky: Seeing FWHM = 8 arcsec (Maxim DL - 10min subframe), Transparency 10/10 Outside Temperature: 65 F CCD Temperature: -30 C Image Processing Tools: Maxim DL: Calibration, deblooming (Starizona Debloomer), aligning, stacking PixInsight: Curves, Deconvolution, noise reduction Photoshop CS2: Curves, Color Correction, Gradient removal (Grad Xterminator), Cleanup HOME GALAXIES EMISSION NEBS REFLECTION NEBS COMETS GLOBULARS OPEN CLUST PLANETARIES LINKS