Messier 16, or the Eagle Nebula, is an emission nebula in the constellation Serpens. It was discovered between 1745 and 1746, and catalogued by Charles Messier in 1764. It is an HII region, with multiple regions of active star formation. The central bright cluster, formed from the nebula's gas, is only 1-2 million years old. The nebula lies at a distance of 7,000 light-years from Earth.
In the centre of the nebula are pillar-like structures which were imaged by NASA's Hubble Space Telescope, and became known as the Pillars of Creation, which themselves harbour areas of star formation. This pillar structures may have been disturbed and destroyed by a supernova which went off 8,000 to 9,000 years ago. The light from this supernova would have reached Earth millenia ago, but the shock front of the supernova would only recently have reached the Eagle Nebula. The light from this interaction will not reach Earth for another 1,000 years.
The observing conditions were mediocre on this night, with poor seeing and adequate transparency. However, technical glitches prevented me from imaging for a few hours, and I only ended up with a couple hours' of data. Nonetheless, the dark sky site and New Moon helped to offset this, and the image turned out alright.
- Canon T3i (modified: missing IR cutoff)
- Skywatcher NEQ6 Pro (Guided: Orion StarShoot, PHD2)
- Vixen VMC200L (1950mm f/9.75)
- 31x 5min exposures @ ISO-1600 (2h 35min) ~ 26.6°C
- 11x Darks
- 40x Flats
- 200x Biases
Processing was done in PixInsight v1.8. The images were calibrated using ImageCalibration and ImageIntegration. The luminance was extracted and TGVDenoise was used on the luminance. Deconvolution was also performed on the luminance, followed by a stretch. On the RGB image, DynamicBackgroundExtraction, BackgroundNeutralization, and ColorCalibration were performed in turn, followed by a stretch. The saturation was increased using CurvesTransformation, and SCNR was applied to remove a green overcast. Convolution was applied slightly to the RGB, and it was combined with the luminance using LRGBCombination.
LocalHistogramEqualization was used to bring out some detail in the centre of the nebula, followed by MorphologicalTransformation to reduce the star sizes. ATrousWaveletTransformV1 was used for sharpening in the brightest parts of the nebula, and the DarkStructureEnhance script was applied slightly. The contrast was improved using CurvesTransformation.
Data was collected on the night of July 3, 2016, at the Irvine Lake Airstrip in Ontario, Canada. This is a Bortle 2 site.