From Monte Alerta to North America
Alqueva´s Dark Sky Reserve | by Year: 2013 | Identifying the sky above - Science & Education | Milky Way & Infrared
In this image we could see two pictures taken at about the same time, day and place, but with a different focal lens, showing a deep travel from Monte Alerta, in Monsaraz (Alqueva Dark sky Reserve – Portugal) to a close approach to North America – not the country on itself – but the well known NGC7000 nebula with North America shape, near the Deneb star, in Cygnus constellation.
In the right picture, we could see part of the milky way region above a tree located in Monte Alerta, taken with a 24mm lens, and where it is visible the nebula IC 1396 and above it, near the Deneb star (top center), the NGC7000.
In the left Deep sky wide field photo, taken with a 70mm lens, we could appreciate a sky of endless colored stars, surrounding “The North America Nebula” (NGC 7000), an emission nebula in the constellation Cygnus, close to Deneb (the blue brightest star in the image center). At its right, we also could see the Sadr region, or IC 1318, a diffuse emission nebula surrounding Sadr or Gamma Cygni star (the second brightest star in the picture).
But why we can find this colorful diversity of stars ? ”Astronomers came to understand that bluer stars are intrinsically brighter because they are more massive than white or red stars, and more massive stars burn much faster and hotter than less massive stars. The bluish type-O stars, for example, are only 30-50 times more massive than yellow-white stars like our sun. But O stars burn a million times brighter, so they have far shorter lifetimes. O and B stars only last a few million years before they die in spectacular supernova explosions, while cooler and less massive K and M stars burn steadily for billions of years”.
Left Picture: Canon 60Da – ISO1600; 70mm f/4 Exp. 119 secs. + Vixen Polarie mount travel. In 5/07/2013 at 3:30 AM (sinlge frame)
Right Picture: Canon 60Da – ISO1600; 35mm f/2 Exp 74 secs. + Vicen Polarie Travel Mount. In 5/07/2013 at 2:07 AM
Below is a special image with the identification of all deep sky objects that can be seen, and the relation with the different focal distances.