Air Glow, Milky Way and the Great Lake Alqueva

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This serene view, captured on the great lake Alqueva, near the “Ermida de São Pedro” in Mourão, one of the regions belonging to the Dark Sky Alqueva Reserve, we find several scientifically interesting things. In the center of the picture we can see the natural colors of the most central region of the Milky Way, located near the Scorpio and Sagittarius constellation, where is it possible to recognize many deep sky objects like the Lagoon Nebula (M8) and the Trifid Nebula (M20). In the image was also possible to register a strong presence of Air Glow (Atmospheric Chemiluminescence) , the further thing I have seen similar to an Aurora, which crossed ahead the region of scorpion, with yellow light, by emissions from sodium atoms in a layer at 92 km. Above it, we could see the green light from oxygen atoms in a layer 90-100 km high. This emission layer is clearly visible from earth orbit.

Reflected in the peaceful lake and due to the polarization effect of water, we could clearly see the entire constellation of Scorpius with the real color of each star naturally saturated, due to this polarization and blurred effect, caused by the slowly movement of water during the long exposure. The orange color of the Red Supergiant Antares could be easily distinguished from the blue color of the Subgiant star, Shaula, in the end of tail. Canon 60Da – ISO 1600; 35mm lens at f/2; Exp. 15 secs. Mosaic of 23 images, taken in 15/06/2013 at 02:35 AM

Below is the annotated version of the image:


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