 |
The Constellation Cygnus resides in the plane of the Milky Way disc and is home to ionised clouds of molecular Hydrogen and dark nebula comprised of dust. The images were captured by Pip Stakkert using the recently acquired and astro-modded Canon 200d DSLR with a Samyang F2 135mm lens on a fixed tripod. 20x8sec lights at F2 and ISO800 stacked and developed using Affinity Photo software (uncropped). |
"The images were taken before the street lights were extinguished and were subject to bright moonlight from a waxing gibbous Moon. We will be excited to see what can be achieved using a higher F value and a longer exposure with this camera lens combination mounted on the Star Adventurer equatorial mount and with the absence of extraneous light pollution. The Samyang F2 135mm fixed manual lens, made in South Korea, is a serious piece of astro-imaging kit!"- Kurt Thrust. current Director of the Jodrell Plank Observatory.
.
Deneb is a first-magnitude star in the constellation of Cygnus, the swan. Deneb is one of the vertices of the asterism known as the Summer Triangle and the "head" of the Northern Cross. It is the brightest star in Cygnus and the 19th brightest star in the night sky, with an average apparent magnitude of +1.25. A blue-white supergiant, Deneb rivals Rigel as the most luminous first-magnitude star. However, its distance, and hence luminosity, is poorly known; its luminosity is somewhere between 55,000 and 196,000 times that of the Sun. Deneb is the most luminous first magnitude star, that is, stars with a brighter apparent magnitude than 1.5. Deneb is also the most distant of the 30 brightest stars by a factor of almost 2. Based on its temperature and luminosity, and also on direct measurements of its tiny angular diameter (a mere 0.002 seconds of arc), Deneb appears to have a diameter of about 200 times that of the Sun; if placed at the center of the Solar System, Deneb would extend out to the orbit of the Earth. It is one of the largest white 'A' spectral type stars known. Deneb is a bluish-white star of spectral type A2Ia, with a surface temperature of 8,500 kelvin. Since 1943, its spectrum has served as one of the stable references by which other stars are classified. Its mass is estimated at 19 solar masses. Stellar winds causes matter to be lost at an average rate, 100,000 times the Sun's rate of mass loss or equivalent to about one Earth mass per 500 years.
Gamma Cygni , officially named Sadr is a star in the northern constellation of Cygnus, forming the intersection of an asterism of five stars called the Northern Cross. Based upon parallax measurements obtained during the Hipparcos mission, it is approximately 1,800 light-years (560 parsecs) from the Sun. It forms the primary or 'A' component of a multiple star system designated WDS J20222+4015 (the secondary or 'BC' component is CCDM J20222+4015BC, a close pair of stars 40" away from γ Cygni. With an apparent visual magnitude of 2.23, Gamma Cygni is among the brighter stars visible in the night sky. The stellar classification of this star is F8 Iab, indicating that it has reached the supergiant stage of its stellar evolution. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. 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. This temperature is what gives the star the characteristic yellow-white hue of an F-type star. Massive stars such as this consume their nuclear fuel much more rapidly than the Sun, so the estimated age of this star is only about 12 million years old
An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically a cloud in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light years, and density from a few to about a million particles per cubic cm.
The North America Nebula (NGC 7000) is one of the most well-known nebulae in Cygnus, because it is visible to the unaided eye under dark skies, as a bright patch in the Milky Way. However, its characteristic shape is only visible in long-exposure photographs – it is difficult to observe in telescopes because of its low surface brightness. It has low surface brightness because it is so large; at its widest, the North America Nebula is 2 degrees across. Illuminated by a hot embedded star of magnitude 6, NGC 7000 is 1500 light-years from Earth.
The Pelican Nebula (also known as IC 5070 and IC 5067) is an H II region associated with the North America Nebula in the constellation Cygnus. The gaseous contortions of this emission nebula bear a resemblance to a pelican, giving rise to its name. The Pelican Nebula is located nearby first magnitude star Deneb, and is divided from its more prominent neighbour, the North America Nebula, by a foreground molecular cloud filled with dark dust. Both are part of the larger H II region of Westerhout 40.
The Pelican is much studied because it has a particularly active mix of star formation and evolving gas clouds. The light from young energetic stars is slowly transforming cold gas to hot and causing an ionization front gradually to advance outward. Particularly dense filaments of cold gas are seen to still remain, and among these are found two jets emitted from the Herbig–Haro object 555. Millions of years from now this nebula might no longer be known as the Pelican, as the balance and placement of stars and gas will leave something that appears completely different.
Credit: Wikipedia
