DUST IN THE WIND
GIANT NEBULAE IN OUR COSMIC NEIGHBOURHOOD
After a longer break I could set up my telescope again and capture some wonderful deep sky objects. Perfect weather, new moon and a little free time: an optimal constellation of circumstances for time-consuming astrophotography.
I chose 3 interstellar cloud of dust so called “nebulae” as targets of my photographic observation: the Veil Nebula, the Iris Nebula and a composition of 3 beautiful objects in one frame: the Sadr Region with the IC1318 Nebula, Gamma Cygni and the NGC 6910 open star cluster. All of these objects are located within a circle of near 5,000 light-years from the Earth, on a galactic scale in our neighbourhood within the Milky Way galaxy.
A nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases. Nebulae are often star-forming regions. In these regions the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter, and eventually will become dense enough to form stars.
The imaging setup was nearly the same for all the three targets: the 8” Altair Astro newtonian telescope on the Sky-Watcher EQ6 mount. The imaging sensor was the modified Canon 700D DSLR camera. For the Iris Nebula and Sadr Region I used a new TS GPU coma corrector for f/4 telescopes which is far better than my old 2 lens corrector from Baader.
The Veil Nebula
The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus. It constitutes the visible portions of the Cygnus Loop, a large but relatively faint supernova remnant. The source supernova exploded circa 3,000 BC to 6,000 BC, and the remnants have since expanded to cover an area roughly 3 degrees in diameter (about 6 times the diameter, or 36 times the area, of the full moon). The distance to the nebula is not precisely known, but some measurements supports a distance of about 1,470 light-years.
The Sadr Region
Sadr is a star in the northern constellation of Cygnus, forming the intersection of an asterism of five stars called the Northern Cross and is among the brighter stars visible in the night sky. Parallax measurements give a distance estimate of 1,800 light years. Compared to the Sun this is an enormous star, with 12 times the Sun's mass and about 150 times the Sun's radius. It is emitting over 33,000 times as much energy as the Sun, at an effective temperature of 6,100 K in its outer envelope.
The Sadr region, or IC 1318, is the diffuse emission nebula surrounding Sadr or Gamma Cygni and is only one of the surrounding nebulous regions; others include the Butterfly Nebula and the Crescent Nebula. It contains many dark nebulae in addition to the emission diffuse nebulae. The nebulous regions around the region are also fairly bright. The nebula located about 4,900 light-years away from Earth and is 100 light-years across. The dark cloud between the two subportion of IC 1318 is about 20 light-years across.
The NGC 6910 is a cluster of tens of stars of brighter magnitude than 12. Its distance has been estimated to be approximately 3710 light years or slightly higher, around 4890 years light; In both cases, the cluster is located in the surrounding Cygnus X large nebula system. His age was estimated at 5-10 million years.