Moravian instruments, Inc., source: https://www.gxccd.com/art?id=550&lang=409, printed: 20.2.2019 1:44:53
Main page Observations
|M16 Eagle Nebula||Updated: 8.1.2019|
|The stream of amazing images from CielBoreal and CielAustral groups apparently never dries. The latest one shows the M16 star cluster and nebula, nicknamed the Eagle Nebula. This object become particularly famous when the detailed Hubble Space Telescope image of the nebula center, called Pillars of Creation, was published.|
The M16 image by CielAustral is captured with G4-16000 camera on 0.5m CDK telescope in Chile. It naturally lacks the details provided by Hubble Space Telescope in the nebula center (but if you download the image in full resolution, the difference is not that big if you consider HST is a multi-billion-dollar space telescope with 2.4m mirror), but is offers much wider field of view and overall impression excellent.
As usual, CielAustral group (Jean Claude Canonne, Nicolas Outters, Philippe Bernhard, Didier Chaplain and Laurent Bourgon) acquired images through both narrow-band Hα, OIII and SII filters to extract maximum details from interstellar nebulosity and in red, green and blue filters to show the nebula in natural colors, similar to humanís eye perception. Total exposure time of narrow-band image exceeds 44 hours, RGB image needed only 5 hours because red, green and blue filters pass much wider portion of the incoming light compared to narrow-band filters and thus achieves good signal-to-noise ratio in much shorter time.
Still, the real-color image above inherits the sharpness and details in nebulosity from the narrow-band image, as it used also Hα data for red color and OIII data for green and blue colors.